The courts have slowed many of Trump’s plans.

Like many such rulings in recent weeks, the judge found that since there was a risk of “irreparable harm” if the administration proceeded on its current course, that access must stop while the federal government and the state attorneys general who sued over the issue present more arguments and evidence to the court.

A flurry of executive orders from the president have already led to lawsuits around the country — cases that are likely to take months to finally resolve. Those that raise untested questions about the scope of executive or legislative authority may take even longer and end up before the Supreme Court.

In recent weeks, the Trump administration has suffered a number of setbacks in court, but those are short-term defeats. It is unclear how many initiatives may ultimately get a green light from the courts.

Critics of Mr. Trump’s efforts to slash the federal work force, limit grant money and end programs he dislikes say many of the moves are contrary to laws passed by Congress and upheld for decades by the courts — particularly civil service protections for federal workers.

So far, courts have also temporarily blocked Mr. Trump’s efforts to freeze federal spending and end birthright citizenship. Earlier this week, a different judge in Washington ruled that the administration cannot publicize the names of F.B.I. agents who worked on cases stemming from the Jan. 6, 2021, riot at the Capitol, amid a larger battle over a possible purge of its rank-and-file. Mr. Trump said on Friday that he would fire agents.

In Washington, lawyers who specialize in employment law have been swamped since the start of the new administration with new clients, consultations and novel legal issues.

Around the country, Democratic state attorneys general have been launching their own counteroffensive to the Trump agenda.

Nineteen state attorneys general, including New York’s Letitia James, filed the suit over Treasury Department data to stop aides of Mr. Musk from what they said was “attempting to access government data to support initiatives to block federal funds from reaching certain disfavored beneficiaries.”

The administration has insisted it is acting legally and that it would be vindicated in court.

Also on Friday, a federal judge in Washington halted some steps undertaken by the administration as it tried to shut down the U.S. Agency for International Development, after a union representing federal workers sued.

Judge Carl Nichols paused the effort to put 2,200 U.S.A.I.D. employees on administrative leave and withdraw nearly all of their overseas workers within a month.

The agency, created by Congress in 2011 as a financial industry watchdog, cannot be closed without congressional action, but its director can freeze most of its actions by halting enforcement, weakening or repealing regulations and softening its supervision of banks and other lenders.

A spokeswoman for the budget office confirmed Mr. Vought’s appointment. Just days earlier, President Trump fired the agency’s Biden-era leader, Rohit Chopra, and replaced him with Treasury Secretary Scott Bessent. Mr. Bessent immediately ordered the agency’s employees to halt nearly all of their work.

On Friday night, the home page of the consumer bureau’s website was updated with a “404: Page not found” message. The change came hours after Elon Musk, the head of the government efficiency program, posted “CFPB RIP,” with an emoji of a gravestone, on his social media platform X. Several members of Mr. Musk’s team arrived at the consumer bureau on Friday morning and gained access to its headquarters and computer systems.

Despite the disruption of the bureau’s home page, the rest of its website remained online, including its database of more than 10 million customer complaints about financial services companies. On Saturday morning, the database was still accepting new complaint submissions.

The consumer bureau’s staff union issued a public statement on Friday about the arrival of Mr. Musk’s associates. It named three of them and warned about the billionaire’s “power grab” and attempt to “defang the only agency that checks the greed of payment providers, as well as auto lenders like Tesla,” a reference to the electric car company run by Mr. Musk. (The union’s post was briefly taken offline; a union spokeswoman said that was caused by a technical error.)

Representatives of the consumer bureau did not respond to requests for comment.

Employees at the bureau spent Friday nervously tracking the Musk team’s arrival and worrying about what it foreshadowed, according to three current and former agency employees. Their agency — created in the aftermath of the housing crisis and Great Recession to increase regulation of mortgage lenders, banks and other financial companies — has long been a target of Wall Street and Republican lawmakers, who have frequently called for its elimination.

Congress has never mustered the votes to kill the bureau, which has also survived two key Supreme Court cases that tried to wipe out the agency on constitutional grounds. Both times, the court preserved the bureau, though justices scaled back its independence by giving the president the power to fire the agency’s director.

Mr. Vought was an author of Project 2025, the conservative blueprint for radically remaking the federal government. A section of Project 2025 devoted to the consumer bureau called it a “highly politicized, damaging and utterly unaccountable federal agency” and said it should be abolished by Congress.

Several Republican lawmakers — led by Senator Ted Cruz and Representative Keith Self, both of Texas — have already introduced legislation seeking to cut the consumer bureau’s funding to $0. (The agency is directly funded by the Federal Reserve, outside the usual congressional appropriations process. The bills would prevent the agency from requesting money from the Fed for its operations.)

More than 80 House Democrats sent a letter on Friday to Mr. Bessent demanding answers to questions about his order to freeze the bureau’s operations.

“We urge you to immediately rescind what appears to be an illegal stop work order,” they wrote.

Madeleine Ngo contributed reporting.

The order was a temporary reprieve to approximately 2,700 direct hires of the U.S. Agency for International Development who were on administrative leave or set to be placed on leave by midnight Friday. For the past two weeks, they and the contractors who work for the agency had been in the throes of a collective panic as the Trump administration began to lay off staff and signaled it planned to decimate the agency.

But the U.S.A.I.D. work force, and the aid industry that relies in large part on the agency’s funding, is still acutely in limbo. On Saturday, U.S.A.I.D. informed employees affected by the order that employees already on administrative leave would be reinstated until the end Friday, Feb. 14, and that no one else would be suspended with pay during that period, according to a copy of the notice viewed by The New York Times. But those employees could still have to wait for weeks, months, or potentially even longer, for a verdict. The case, which was brought on behalf of unions representing the workers, is expected to go to the Supreme Court, and it is unclear whether the jobs will ever exist again.

The Trump administration’s announcement this week that U.S.A.I.D. would dismiss almost all of its contractors and that most Foreign Service officers and other direct hires would be put on indefinite administrative leave set off a panic around the globe, as Americans posted in missions abroad scrambled to dismantle and reassemble their lives.

The announcement gave Foreign Service officers just 30 days to depart their posts and return to the United States if they wanted the U.S. government to pay for their relocation, forcing nearly the entire diplomatic staff to plan the sort of swift exit that normally only takes place during coups and wars.

Many employees with children had to decide whether to pull them out of school immediately, or leave families behind until the end of the school year. Some with medical conditions, including late-stage and high-risk pregnancies, worried about the dangers of traveling and the status of their health care. Several agonized over what to do about pets, because it was not possible to procure the paperwork necessary to enter the United States in just a few weeks.

The reductions at U.S.A.I.D. appear to have been driven largely by Elon Musk, the tech magnate President Trump deputized to make budget cuts across the government, and Pete Marocco, the State Department’s director of foreign aid, whom Secretary of State Marco Rubio appointed this week to run the day-to-day business of U.S.A.I.D.

Mr. Rubio, who has assumed overall authority of U.S.A.I.D., tried to tamp down the fears, encouraging people to apply for waivers to delay travel and arguing that the Trump administration was “not trying to be disruptive to people’s personal lives.”

But as stop-work orders and reports of massive cuts at the agency rippled across the global aid industry, and scores of nongovernmental organizations and consulting firms that relied on the agency’s funding laid off staff, the agency’s workers braced for its potential end.

One American posted to a U.S.A.I.D. mission in Africa said that he and his wife, a Foreign Service officer, had both been suspended.

“Two weeks ago we were two gainfully employed people with onward assignments, and now we’ve seen the entire industry decimated and we’re returning to the U.S. without jobs,” he said.

He, like many others, spoke on the condition of anonymity, as those still on the agency’s payroll have been instructed not to publicly discuss the changes underway. Employees fear that flouting the order could jeopardize whatever benefits they might still be eligible for, such as pensions and severance pay — though it was unclear if the Trump administration would honor such obligations.

On Thursday, a subset of U.S.A.I.D. employees began receiving notices that they had been deemed “essential,” meaning they would not be suspended or laid off — for now.

“This is your formal notification that you are expected to keep working, effective immediately, and until notified otherwise,” the emailed notification said, according to a copy reviewed by The New York Times.

It was not immediately clear how many employees had been deemed essential. On Thursday afternoon, senior U.S.A.I.D. leaders were told that the Trump administration planned to reduce the agency’s staff to about 290, according to three people informed directly about the details of the call. By Friday morning, however, senior agency officials were being told that the number of retained employees was 611, according to two people familiar with the internal guidance.

Some speculated that the number of people retained might climb slightly higher, as bureau and regional leaders fought to preserve as many positions as possible to continue the agency’s lifesaving work.

Either way, the cuts to a work force of more than 10,000 promised to be drastic.

“What is happening is devastating, it’s hard to put it into words, but it’s devastating,” said Maria Carrasco, who had worked for the aid agency or projects abroad it had funded for the last 25 years, she said, before being terminated with other contractors last week. “We are people who put our sweat and tears in to these organizations, because we believe in the ultimate goal of helping people. And now it’s been erased.”

The moves against the U.S.A.I.D. work force began in earnest on Jan. 28, four days after the stop-work orders were issued.

Samantha Cooper, a contractor whose employment was terminated, had been working in maternal and child health and nutrition at the aid agency, and was set to begin a new job this past Monday in the Office of H.I.V./AIDS. Within days, she went from being excited about an upcoming career milestone to straining to make ends meet.

“I’m having to file for unemployment, which doesn’t even cover rent; food stamps, which — that’s fine, it at least gets me groceries,” she said in a telephone interview. Her medical coverage ran out on Friday last week.

Ms. Cooper, who is based in Tulsa, Okla., said she felt luckier than most.

“I have co-workers that are going through I.V.F., and they’ve lost all their benefits; people going through cancer treatments and with parents on hospice — and they were the breadwinners,” she said. “I feel privileged to say this is only what I’m struggling with. I know there are so many others having to deal with that, and it is literally going to break them.”

That was the fear for one Foreign Service officer in Asia who discovered this week that an immediate family member needed to be evacuated for a life-threatening health condition, only to be told by superiors that amid the dissolution of U.S.A.I.D., there was no funding available for emergency medical travel. Their only option, the officer was told, would be to immediately return to the United States, where they have nowhere to live, and leave their belongings and pets behind.

Another Foreign Service officer working at a mission in Africa wrestled with how to break the news to her two young children.

She also worried that she and her spouse, who also works in development, would have to live off the savings they had hoped to put toward a house if they both soon found themselves out of work.

“It just feels like the entire sector is sinking, and so how am I going to find a job?” she said, speaking on the condition of anonymity, like others, for fear of retaliation. “All I know is development, all I know is public health — I’ve dedicated my life to this. What other skills do I have?”

The decimation of U.S.A.I.D. has set off a domino effect, as contractors, nongovernmental organizations and consulting firms that rely on funding from the agency for their projects also are forced to make cuts. At least 10,000 American jobs in the sector have already disappeared, according to InterAction, which represents a number of organizations specializing in foreign aid.

“It’s the evisceration of the sector,” Tom Hart, the president and chief executive officer of InterAction, said.

Employees of nongovernmental organizations and companies that rely on U.S.A.I.D. funding said they had effectively been blocked from accessing any funding through the agency’s accounting system, and in some cases, had months of expenses with no guarantee that the federal government would reimburse them.

Resonance, a development consulting firm that employed about 150 people around the world, is an example of a small company taking a big hit. The firm did about 75 percent of its business with U.S.A.I.D. before the contraction. It has bills going back to November that the agency has yet to cover, Steve Schmida, its co-founder, said in an interview.

“We’re being forced to carry a huge amount of cost with no clarity if and when we will get paid or reimbursed,” Mr. Schmida said, adding that he had to lay off almost 90 percent of his U.S.-based staff. He is going without pay for three months to help free up funds to keep his business afloat, he said.

But as news of the drastic staff reductions took hold, he was losing hope that the government would ever cover the funding his firm had been promised.

“It’s just been a catastrophe,” he said of the U.S.A.I.D. cuts, adding: “I think it’s dawning on everyone that this is over.”

Edward Wong contributed reporting from Bangkok and Chris Cameron from Washington.

Mr. Trump has not yet described his plans for NOAA, whose research is considered essential to the study of climate change, or for the Weather Service, of which it is a part. But this week, staff members participating in Elon Musk’s efforts to downsize the government arrived at the agency, as they have at several others since Mr. Trump’s inauguration.

Many of the Trump administration’s early actions have followed a blueprint set out by Project 2025, a policy blueprint created by the conservative Heritage Foundation. The 900-page document, published in 2023, envisioned a significantly pared down federal government, and it may offer clues to the fate of the Weather Service.

But first, some history.

It started with some shipwrecks.

The first national meteorological service in the United States was established in response to tragedy. Across just two years, 1868 and 1869, more than 500 people were killed and more than 3,000 vessels sunk or damaged, many by storms, on the Great Lakes, according to “A Century of Weather Service,” a history of the agency by Patrick Hughes.

By February 1870, President Ulysses S. Grant, pushed by calls for a storm warning system, formally established the country’s first meteorological service as part of the U.S. Army.

This service was part of the Department of Agriculture and later moved to the Department of Commerce. In 1970, the National Weather Service was officially established when President Richard Nixon created NOAA, aimed at providing “better protection of life and property from natural hazards,” within Commerce.

Since then, Congress has considered restructuring NOAA and its offices, which besides the Weather Service include the National Ocean Service; Office of Oceanic and Atmospheric Research; National Environmental Satellite, Data and Information Service; National Marine Fisheries Service; and the Office of Marine and Aviation Operations. Congress has also considered moving NOAA to another department or making it an independent agency.

And for several decades, conservatives in the pursuit of free market goals have advocated increasing the role of the private sector in American weather forecasting.

How a forecast works now

Today, the Weather Service is a dispersed operation. Many of its more than 4,000 employees work from 122 forecast offices across the country, where they continuously monitor local conditions, issue multiple daily forecasts and release warnings ahead of dangerous weather.

Its staff also operates some additional offices with a specialized remit, including one that is tasked with monitoring flooding, units that advise air traffic controllers, and the National Hurricane Center.

By its own estimate, the Weather Service collects over six billion weather observations a day. To create a forecast, a meteorologist at a local office may analyze some of those data points, consult weather models and make judgments based on expertise.

But the service’s mission goes beyond forecasting. In April 2011, after a large — and accurately predicted — tornado outbreak killed more than 300 people across the South, the department began providing advice to emergency agencies and public officials. It started telling people what to do with the information its forecasts were providing.

Rob Dale, the deputy emergency manager for Ingham County, Mich., works closely with the Weather Service. “Michigan State University’s in our jurisdiction, and they send a meteorologist out to every football game here, just to monitor the lightning threat or severe weather threat,” Mr. Dale said. “There’s someone right in the room as we go through the decision-making process.”

The Weather Service provides its forecasts and warnings to the public free of charge. NOAA’s observational data, from the agency’s vast network of satellites, buoys, weather balloons and sensors, is also available at no cost; companies like AccuWeather, Google and Apple use it to power their weather products.

The Weather Service estimates that its services cost every American resident $4 per year.

How the Weather Service could change

The chapter of the Project 2025 document that includes proposals for NOAA describes the agency as a “colossal operation that has become one of the main drivers of the climate change alarm industry,” and calls for it to be “broken up and downsized.”

It proposes that the Weather Service focus on its data-gathering services and “fully commercialize” its forecasting operations.

Mr. Trump’s nominee for Commerce Secretary, Howard Lutnick, a billionaire Wall Street executive, told senators during his confirmation hearing in late January that he did not agree with Project 2025’s proposal to dismantle NOAA and eliminate many of its functions. He also said, during questioning from Senator Amy Klobuchar, Democrat of Minnesota, that he would maintain the Weather Service.

But in the same exchange with Ms. Klobuchar, Mr. Lutnick also appeared to allow for the possibility that the private sector could take up the forecasts that have traditionally been Weather Service work. “I think we can deliver the product more efficiently and less expensively, dramatically less expensively,” he said, “but the outcome of delivering those services should not be changed.”

The Weather Service during Mr. Trump’s first term

Mr. Trump has shown a preference for the private sector when it comes to weather. During his first term, he nominated Barry Myers, the former chief executive of AccuWeather, one of the nation’s largest private weather forecasters, to lead NOAA.

Mr. Myers remained unconfirmed by the Senate for more than two years. He withdrew from the process in 2019, criticizing Democrats who had voiced concerns over his possible conflicts of interest.

(In a statement last year, AccuWeather appeared to distance itself from Project 2025’s proposal to fully privatize the weather system. “AccuWeather does not agree with the view, and AccuWeather has not suggested, that the National Weather Service (NWS) should fully commercialize its operations,” its chief executive, Steven R. Smith, said. The public-private partnership approach in forecasting “has saved countless lives,” he said.)

Mr. Trump’s influence on the Weather Service was felt elsewhere during his first term. In a 2019 episode that came to be known as “Sharpiegate,” Mr. Trump was at odds with government meteorologists over the forecast for Hurricane Dorian. After he included Alabama on a list of states that he claimed would be hit by the storm, a Weather Service office in Birmingham clarified on social media that the hurricane would not affect the state. Days later, during a news briefing, Mr. Trump brandished an illustration of the storm’s path that had been altered with a thick black marker to include Alabama.

Bowing to pressure, Neil Jacobs, then NOAA’s acting administrator, issued a statement that supported Mr. Trump’s assertions and criticized the Alabama forecasters for their post. An investigation found Dr. Jacobs had violated the agency’s policy for scientific integrity in issuing the statement.

This week, Mr. Trump nominated Dr. Jacobs to the post of NOAA administrator again.

The future of weather

If confirmed, Dr. Jacobs would lead NOAA at a time when the balance of its public-private partnership may already be in flux. Studies show extreme weather events are becoming more frequent and more intense as a result of climate change. At the same time, weather models driven by artificial intelligence have demonstrated an ability to produce forecasts that are more accurate than traditional weather models.

A crop of private companies that use A.I. to build their forecasts is leading the charge to adopt the technology more widely. Companies are now increasingly operating their own weather observation instruments, though many also still use NOAA data. In recent years, NOAA, too, has begun supplementing the data it collects with data purchased from the private sector.

In Michigan, Mr. Dale worries that commercializing the Weather Service’s forecasting could set up a pay-to-play system for lifesaving warnings. “If someone says, ‘Hey, if you want a tornado warning for your county, you’re going to have to pay us, $100,000 a year,’ that’s just not viable,” he said. There’s no spare money in most county budgets these days to do something like that.”

Louis Uccellini, who was the Weather Service director between 2013 and 2022 and described himself as “one of the biggest supporters” of the private sector’s role in weather, said he believed not all the department’s work could be successfully contracted out. “Public service is not measured by the bottom line,” he said, “but by how well we serve society with the resources allocated by Congress.”

The cable, a copy of which was obtained by The New York Times, said the absence of experienced agency employees in Mozambique would leave in limbo 114 active funding awards and 225 more junior workers, likely local citizens, “that will all require management and supervision.”

The cable paints a picture of chaos about to descend on the U.S. diplomatic mission and vulnerable citizens of Mozambique because of the imminent departure of the experienced aid workers, many of whom are Foreign Service officers with many years or decades of service.

“As a result, we are unable to put in place sufficient protections, procedures and management to prevent fraud, waste, abuse and mismanagement,” Mr. Vrooman wrote in the cable, which is labeled “sensitive but unclassified.”

Other chiefs of missions across Africa are sending similar cables to Mr. Rubio in a rare coordinated effort, said a person with knowledge of the cables.

Mr. Rubio announced on Monday that he would be acting administrator of the U.S. Agency for International Development, or U.S.A.I.D., ending its independent status, and was appointing Pete Marocco, a divisive State Department official who worked in the first Trump administration, to oversee daily operations.

The move came after a task force led by Elon Musk, the billionaire adviser to President Trump, worked with Mr. Marocco to force drastic cuts to the agency, freeze much of its technology infrastructure and lock workers out of electronic systems, essentially halting the agency’s operations in advance of complete dismantlement.

The top officials then ordered all U.S.A.I.D. employees around the world — more than 10,000 workers — to go on leave as of Friday and said all direct hires must return to the United States within 30 days. Those orders have now been temporarily blocked by a judge.

On Jan. 20, Mr. Trump signed an executive order halting foreign aid as his major foreign policy action, and Mr. Rubio has said officials will do a 90-day review of all such aid. The total government budget for U.S. foreign aid across several agencies, much of it humanitarian assistance, is about $60 billion per year, less than 1 percent of the federal budget.

In the cable from the embassy in Maputo, the capital of Mozambique, Mr. Vrooman, a diplomat of nearly 35 years who has also served as ambassador to Rwanda, argued for Mr. Rubio to allow five aid agency employees to be exempted from the forced departure “to complete required property and management controls and contract wind-down operations, if ordered, in a manner that safeguards U.S. national interests and minimizes legal liabilities” to the U.S. government.

Mr. Vrooman also argued for exemptions to eight health positions to try to keep lifesaving humanitarian assistance programs running. Mr. Rubio has granted a waiver to the blanket foreign aid halt for such programs, but many American officials say they cannot keep the programs running for various reasons. The absence of the necessary health employees “will jeopardize the effectiveness of the waiver to save lives,” Mr. Vrooman wrote, in bold letters.

He noted that U.S.A.I.D. supports 40 active lifesaving and emergency active field programs, and that in Mozambique more than two million people depend on the provision of antiretroviral drugs to prevent the spread of H.I.V., AIDS and strains of tuberculosis.

One U.S.A.I.D. program that requires an experienced manager to be present in Mozambique provides essential treatment for 389,000 people living with H.I.V., Mr. Vrooman noted.

He also wrote in the cable that U.S.A.I.D. families with school-age children should be allowed to stay in the country until mid-June, when the school year ends. Mr. Vrooman did not immediately reply to an email seeking comment.

Ms. Shogan announced her firing on her professional LinkedIn page.

“This evening, President Trump fired me,” Ms. Shogan wrote. “No cause or reason was cited. It has been an honor serving as the 11th Archivist of the United States. I have zero regrets — I absolutely did my best every day for the National Archives and the American people.”

The White House did not immediately respond to a request for comment. But in a post on social media, Sergio Gor, who runs the presidential personnel office, confirmed Ms. Shogan’s dismissal.

Ms. Shogan, the first woman appointed to the typically apolitical role, was something of an unusual target for Mr. Trump. She was not involved in the criminal investigations into Mr. Trump’s handling of classified documents, and was not the leader of the Archives when it raised concerns about Mr. Trump.

She had also had high-profile clashes with the Biden administration. Last year, she blocked attempts by Democratic lawmakers to add a 28th amendment, the Equal Rights Amendment, to enshrine gender equality into the Constitution. Ms. Shogan refused to publish the amendment on the grounds that it had not met the necessary requirements, even after President Joseph R. Biden, who appointed her, declared that it did.

But her affiliation with an agency despised by Mr. Trump appeared to be all the justification he needed to dismiss her. The Archives, which is responsible for issuing and preserving the nation’s records, alerted the Justice Department in early 2022 about Mr. Trump’s potential mishandling of classified documents after it learned that he had taken more than a dozen boxes of presidential records to Mar-a-Lago, his private residence and club in Florida, after he left office.

Ms. Shogan began leading the agency in May 2023. But on the day that his electoral win was slated to be certified last month, Mr. Trump vowed that he would replace Ms. Shogan during an interview with a conservative radio host who told Mr. Trump his “problems” with the documents case came about because the archivist at the time “hated you.”

“I think I can tell you that we will get somebody — yes,” Mr. Trump said. “We will have a new archivist.”

The F.B.I. executed a search warrant at Mar-a-Lago in 2022 after trying for more than a year to get Mr. Trump to return documents. The case eventually led to Mr. Trump’s being charged by the special counsel Jack Smith with mishandling classified documents and obstructing the Justice Department investigation.

The case was ultimately dismissed last year by a judge Mr. Trump had appointed on the grounds that Mr. Smith had been unlawfully appointed to his job.

It follows Mr. Trump’s accusation on his social media site on Sunday that the South African government was engaged in a “massive Human Rights VIOLATION, at a minimum.” He vowed a full investigation and promised to cut off aid.

“South Africa is confiscating land, and treating certain classes of people VERY BADLY,” the president wrote in the post. “It is a bad situation that the Radical Left Media doesn’t want to so much as mention.”

The order was stunning in providing official American backing to long-held conspiracy theories about the mistreatment of white South Africans in the post-apartheid era.

Mr. Trump has made repeated claims without evidence that echoed those conspiracy theories. In 2018, he ordered his secretary of state to look into “the large scale killing of farmers” — a claim disputed by official figures and the country’s biggest farmers’ group.

Mr. Trump’s recent comments were in reference to a policy that President Cyril Ramaphosa of South Africa signed into law last month.

The law, known as the Expropriation Act, repeals an apartheid-era law and allows the government in certain instances to acquire privately held land in the public interest without paying compensation — something that can be done only after a justification process subject to judicial review.

The order from Mr. Trump came a day after Mr. Ramaphosa delivered his State of the Nation address with a defiance that appeared to be a reference to the American president’s accusations.

“We will not be bullied,” he said. The South African leader vowed to stand united in the face of what he called “the rise of nationalism and protectionism.”

“We will speak with one voice in defense of our national interest, our sovereignty and our constitutional democracy,” he said.

In addition to the halt in foreign aid, Mr. Trump ordered officials to provide “humanitarian” assistance to Afrikaners and to allow members of the white South African minority to seek refuge in the United States through the American refugee program.

Since the transition to democracy in 1994, the South African government has taken a willing-seller approach to try to transfer the ownership of more land to the country’s Black majority. The new law, with limited exceptions to that approach, came as many Black South Africans have argued that Nelson Mandela and other leaders did not do enough to force the white minority to give up wealth that had been accrued during apartheid.

South Africa’s colonial regimes were particularly brutal in dispossessing Black people of their land and forcefully removing them. Despite the efforts of postcolonial governments, the result remains clear to this day: White South Africans, who make up 7 percent of the population, own farmland that covers the majority of the country’s territory.

In an earlier executive order, Mr. Trump had demanded a three-month pause in the United States’ refugee program, blocking the admission of desperate people fleeing war, economic strife, natural disasters or political persecution. Friday’s order appeared to make white South Africans an exception to the broader halt.

While it is not clear whether he had an influence on the president’s order, Elon Musk, the billionaire who has become a close adviser to the president, is from South Africa. In 2023, Mr. Musk posted similar far-right conspiracy claims about South Africa on X, the social media platform he owns.

“They are openly pushing for genocide of white people in South Africa,” Mr. Musk wrote.

Mr. Ramaphosa and Mr. Musk spoke by phone after that social media post, with the South African president trying to clarify what his administration has called “misinformation” peddled by Mr. Trump.

In much of South Africa, Mr. Trump’s attacks in recent days inspired a rare bit of political unity, with leftist, centrist and even some far-right activists all saying that the American president’s characterization of the land transfer law was wrong.

His comments amplified a long-held grievance among some white South Africans who claim they have been discriminated against by the Black-led government after apartheid. But Mr. Trump’s comments also angered many South Africans, who saw the law as a necessary means of redressing historical injustice.

Since 1994, when South Africa became a democracy, the country has enjoyed a close relationship with the United States. Barack Obama visited there several times during his presidency, including when he attended the memorial service for Mr. Mandela, who had been imprisoned for 27 years before becoming the country’s president.

But Mr. Trump’s actions on Friday made it clear that he does not view the relationship in the same way.

South Africa received more than $400 million in aid from the United States in 2023, almost all of which went to funding efforts to fight H.I.V. and AIDS. The government has said that American funding makes up about 17 percent of its budget for battling H.I.V.

Far-right white Afrikaners applauded Mr. Trump’s attacks on South Africa’s government in recent days.

Ernst Roets, the executive director of the Afrikaner Foundation, which lobbies for international support of the interests of Afrikaners, said that while the government was not seizing land, it was trying to create a legal and policy framework to be able to do so.

The expropriation law opens the door to abuse, Mr. Roets said, because the government “can justify a lot of things under the banner of public interest.” But even Mr. Roets and his group had not called on Mr. Trump to broadly cut aid to South Africa, instead seeking targeted actions against government leaders.

After Mr. Trump first commented about land confiscation, the South African government tried to broker a conversation between its foreign minister and Marco Rubio, the secretary of state, according to Ebrahim Rasool, South Africa’s ambassador to the United States. But the Trump administration did not respond, he said.

Mr. Newsom signed a pair of bills with no news cameras, bringing to a quiet end an effort he launched with vigor two days after the election. Three months ago, he asked state lawmakers to move quickly to defend the state from presumed incursions by Mr. Trump and called for a special legislative session.

The governor seemed to be positioning himself as a national leader of the Democratic resistance in the days following the election. But he has treaded more cautiously in recent weeks after the president threatened to withhold disaster aid from California. On Wednesday, he met with Mr. Trump for more than an hour in the Oval Office.

The bills signed by Mr. Newsom passed on a party-line vote, but proved trickier than first thought in the state’s Democratic-led Legislature as Mr. Trump and Republican state lawmakers have tried to distinguish between the deportation of criminal undocumented immigrants and others they say they are not targeting for now.

Democratic lawmakers, in an attempt to inoculate themselves from arguments that they were using state dollars to help violent offenders, added a message to clarify that the state legal aid was not meant to help immigrants with criminal backgrounds — a clear acknowledgment of Republican criticisms and the mood of the electorate.

Mr. Newsom also made that point in a signing statement. “None of the funding in this bill is intended to be used for immigration-related legal services for noncitizens convicted of serious or violent felonies,” the governor wrote.

He encouraged legislators to pass a new law making it clear that this funding will be allocated based on restrictions in existing state law. Those restrictions prohibit people convicted of violent felonies from benefiting from state grants for immigration-related legal services.

Earlier this week, the legislation set off fiery debate in the State Capitol. Republicans argued that the special legislative session called by Mr. Newsom was an ill-timed political stunt that would harm California’s efforts to seek federal funding to help Los Angeles recover from last month’s wildfires, which killed 29 people and leveled thousands of homes. Democrats, who hold more than two-thirds of the state legislative seats, pressed the need to gird for legal battles with the Trump administration.

“Californians are being threatened by an out-of-control administration in Washington that doesn’t care about the Constitution, that thinks there are no limits to its power,” Robert Rivas, the Democratic Assembly speaker, said as lawmakers passed the bills on Monday. “I can say with clarity: We do not trust President Donald Trump.”

Democratic state legislators had planned to send the bills to Mr. Newsom last week, but Republicans raised concerns that the legal aid could help defend immigrants accused of violent crimes. They emphasized that message in Sacramento the same week that Mr. Trump signed the Laken Riley Act, which calls for the authorities to detain unauthorized immigrants who are charged with crimes ranging from violent offenses to misdemeanors such as burglary and shoplifting.

“The least you could do is stop spending taxpayer funds to keep violent criminals in our country,” said Carl DeMaio, a Republican assemblyman.

The argument initially concerned some Democrats, and State Assembly leaders postponed their vote while they sought assurances that the legislation as written wouldn’t wind up helping people with criminal records.

The rightward shift that the nation experienced in the last election was evident in California state contests as well. Republicans flipped three state legislative seats previously held by Democrats, and Mr. Trump won 10 counties that former President Joseph R. Biden Jr. carried in 2020.

Two of the counties fell partly in a Central Valley district represented by Esmeralda Soria, a Democratic assemblywoman. Yet she said she had no qualms about voting for the legal aid bill to support undocumented immigrants.

“When you talk to people in my district, they care about our local economy, and they understand that we need immigrants,” she said. “Who’s going to pick their fruit and vegetables?”

The legislation lays the groundwork for California to resume its role of jousting with the federal government. The state sued the Trump administration more than 100 times during the president’s first term and has been involved in three lawsuits challenging his orders since Mr. Trump re-entered the White House last month.

“Joe, you’re fired. Make America Great Again!” Mr. Trump wrote in his signature all-caps style.

As a practical matter, the decision will have little import. Former presidents get episodic briefings partly as a courtesy, and partly because, in times of a more bipartisan spirit, sitting presidents sometimes call former occupants of the office for advice, or to ask about their experience in handling a delicate diplomatic negotiation.

But there seems to be no chance of Mr. Trump ever calling his predecessor. Instead, the security clearance revocation serves primarily to add to a remarkable list of grievance-driven acts by Mr. Trump in his first 19 days in office.

The president has already withdrawn federal protection for five former members of his first administration. Those included some officials — former Secretary of State Mike Pompeo, former Defense Secretary Mark T. Esper and John R. Bolton, the former national security adviser — whom a stream of intelligence suggests Iran has plotted to kill.

On the first day of his presidency, Mr. Trump signed an order revoking the security clearances for 51 former senior intelligence officials who signed an open letter in 2020 saying that the discovery of a laptop owned by Hunter Biden, Mr. Biden’s son, “has all the classic earmarks of a Russian information operation.” Later investigation found no apparent Russian involvement.

But even then, Mr. Trump stopped short of going after his predecessor, who earlier in the day he had waved goodbye to as Mr. Biden left the Capitol in a helicopter.

That hesitance ended on Friday evening, as Mr. Trump headed to Mar-a-Lago, his Florida estate and club. He then plans to go to New Orleans to attend the Super Bowl on Sunday.

“I think it is just performative,” Beth Sanner, who gave Mr. Trump his highly classified Presidential Daily Brief during his first term, said in an interview on Friday night.

“The only reason a former president needs briefing is to prepare before they speak to foreign leaders, or because they have some other kind of engagement that relates to foreign policy,” Ms. Sanner said. “But there is no real reason to do it except before those moments, and in this case it’s hard to imagine Biden is really going to need it.”

In his social media posting, Mr. Trump cited an investigation by Robert K. Hur, a special counsel appointed to examine how a number of classified documents from Mr. Biden’s time as vice president ended up in his garage. (Unlike Mr. Trump, Mr. Biden was not prosecuted over his handling of classified material.)

“The Hur Report revealed that Biden suffers from ‘poor memory’ and, even in his ‘prime,’ could not be trusted with sensitive information,” Mr. Trump wrote, in the latter case misstating the report’s findings. “I will always protect our national security.”

The timing was curious: All week there have been questions about whether young employees of the so-called Department of Government Efficiency had appropriate security clearances to enter payment systems in the Treasury Department, or gain access to personnel records at the U.S. Agency for International Development, which Mr. Trump and Elon Musk, acting on his behalf, were dismantling.

Mr. Trump was clearly riled by the memory, four years ago, of how Mr. Biden stripped him of his clearance.

“What value is giving him an intelligence briefing?” Mr. Biden said in an interview with Norah O’Donnell of CBS News at the time. “What impact does he have at all, other than the fact he might slip and say something?”

Mr. Biden’s move to deprive Mr. Trump of the traditional briefings was surprising at the time: Continued briefings for ex-presidents have been an institutional staple of Washington for decades, a bipartisan tradition in an era of greater and greater partisanship. But in breaking a precedent, it also seemed to create one.

The obvious question raised by Mr. Trump’s action is whether he considers it a final settling of scores between the country’s second-oldest and oldest presidents, or whether it is an opening salvo.

Already this week Mr. Trump has been hunting down Biden-era appointees and firing them, even from institutions — like the John F. Kennedy Center for the Performing Arts or Voice of America — that have long enjoyed an air of bipartisanship. Republicans in Congress have promised more investigations into the Biden presidency, which Mr. Trump often called the “Biden Crime Family,” which could put those close to Mr. Biden in legal jeopardy.

Theoretically, Mr. Trump could even pull Mr. Biden’s Secret Service detail. But that seems unlikely, because it could invite reciprocal action against Mr. Trump when he leaves office.

Judge Engelmayer ordered any such official who had been granted access to the systems since Jan. 20 to “destroy any and all copies of material downloaded from the Treasury Department’s records and systems.” He also restricted the Trump administration from granting access to those categories of officials.

The defendants — President Trump, Treasury Secretary Scott Bessent and the Treasury Department — must appear on Feb. 14 before Judge Jeannette A. Vargas, who is handling the case on a permanent basis, Judge Engelmayer said.

The situation could pose a fundamental test of America’s rule of law. If the administration fails to comply with the emergency order, it is unclear how it might be enforced. The Constitution says that a president “shall take Care that the Laws be faithfully executed,” but courts have rarely been tested by a chief executive who has ignored their orders.

Federal officials have sometimes responded to adverse decisions with dawdling or grudging compliance. Outright disobedience is exceedingly rare. There has been no clear example of “open presidential defiance of court orders in the years since 1865,” according to a Harvard Law Review article published in 2018.

Saturday’s order came in response to a lawsuit filed on Friday by Letitia James of New York along with 18 other Democratic state attorneys general, charging that when Mr. Trump had given Mr. Musk the run of government computer systems, he had breached protections enshrined in the Constitution and “failed to faithfully execute the laws enacted by Congress.”

The lawsuit was joined by the attorneys general of Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, North Carolina, Oregon, Rhode Island, Vermont and Wisconsin.

They said the president had given “virtually unfettered access” to the federal government’s most sensitive information to young aides who worked for Mr. Musk, who runs a program the administration calls the Department of Government Efficiency, or DOGE.

While the group was supposedly assigned to cut costs, members are “attempting to access government data to support initiatives to block federal funds from reaching certain disfavored beneficiaries,” according to the suit. Mr. Musk has publicly stated his intention to “recklessly freeze streams of federal funding without warning,” the suit said, pointing to his social media posts in recent days.

In her own social media post on Saturday, Ms. James reiterated that members of the cost-cutting team “must destroy all records they’ve obtained,” and added: “I’ve said before, and I’ll say it again: no one is above the law,” she wrote.

New Jersey’s attorney general, Matthew J. Platkin, said in a post on Saturday that the injunction meant “the world’s richest man has been stopped from stealing your data.”

Efforts to reach press officers at the White House were not immediately successful on Saturday morning.

In a statement on Thursday, after the attorneys general said they would sue, a spokesman for the president said that Mr. Musk’s team was acting legally. “Slashing waste, fraud and abuse, and becoming better stewards of the American taxpayer’s hard-earned dollars might be a crime to Democrats, but it’s not a crime in a court of law,” said the spokesman, Harrison Fields.

Although the court order mandates an immediate halt to the Musk employees’ access to the Treasury Department’s payment system, it was not immediately clear when or if they would fully comply. Nor was it clear how the attorneys general would monitor the administration’s actions.

In a previous action, 23 attorneys general sued Mr. Trump’s freeze of federal grants and won a temporary pause on Jan. 31, with a judge ordering the administration to stop withholding funds. However, on Friday, the coalition appealed to the judge again, saying that the money was still being withheld from states, grantees and programs.

Mr. Trump has had scant success in the courts in years past. His first administration succeeded in only about 23 percent of the legal challenges against the actions of his agencies, a review found, while prior administrations won about 70 percent of the time.

But Mr. Trump’s new term is already a thing apart.

The administration’s “shock and awe” approach since he was inaugurated last month has seen new policies and actions arrive at breakneck speed. On his first day in office, Mr. Trump pardoned members of the mob that attacked the Capitol on Jan. 6, 2021. He has signed dozens of executive orders, withdrawn the country from international agreements and even tried to install himself as chairman of the John F. Kennedy Center for the Performing Arts in Washington.

The aggressive approach is beginning to be tested by scores of lawsuits on a host of issues, but the legal system’s ability to restrain the administration remains uncertain.

If federal officials fail to comply with the Saturday order limiting DOGE, the judge may hold them in contempt, said Daniel C. Richman, a Columbia Law School professor and a former federal prosecutor in Manhattan. Courts have done that in the past, he said, “albeit rarely.”

“A contempt citation can come with fines, more likely imposed on the officials rather than the government itself, and even possible imprisonment,” Mr. Richman said.

In 2002, Interior Secretary Gale A. Norton was held in contempt for failing to fix the department’s management of billions of dollars in royalties earned on American Indian land. The following year, a federal appeals court found that she could not be held in criminal contempt for problems that existed before her tenure.

Although contempt findings can be “devoid of sanction, they nonetheless have a shaming effect,” which is often enough to spur officials to compliance, Nicholas Parrillo, a professor at Yale Law School, wrote in the 2018 Harvard Law Review article.

However, he wrote, the “rise of partisan polarization could potentially fracture the pro-compliance community so badly that members of one party would refuse to acknowledge the shame of a contempt finding against a member of their own camp.”

Since Mr. Trump entered office last month, Mr. Musk has so far been unconstrained. When DOGE first turned its attention to the Treasury Department, a top official refused to give members access, leading to a standoff. The official, David Lebryk, was put on leave before suddenly retiring.

Almost immediately, Mr. Musk’s team was given access to the government’s most fundamental computer data, including the U.S. Treasury Department’s payment system, which is used to disburse funds including Social Security benefits, veteran’s benefits and federal employee wages.

The system — which channels about 90 percent of the payments for the U.S. government, which spent about $6.75 trillion last fiscal year — pays funds directly to people in the states, as well as to state governments, the suit says.

Before Mr. Trump took office last month, access was granted to only a limited number of career civil servants with security clearances, the suit said. But Mr. Musk’s efforts had interrupted federal funding for health clinics, preschools and climate initiatives, according to the filing.

The money had already been allocated by Congress. The Constitution assigns to lawmakers the job of deciding government spending.

“President Trump does not have the power to give away Americans’ private information to anyone he chooses, and he cannot cut federal payments approved by Congress,” Ms. James said in a statement. “Musk and DOGE have no authority to access Americans’ private information and some of our country’s most sensitive data.”

The case is one of many resisting Mr. Trump’s aggressive actions since he took office last month.

Three unions this week sued the U.S. Office of Personnel Management, the government’s human resources division, to block an effort to persuade roughly two million federal employees to resign.

Two anonymous sets of F.B.I. agents and employees sued to keep the Trump administration from releasing the identities of people who worked on investigations into the Capitol riots on Jan. 6, 2021. They won an order on Friday requiring the administration to keep their names secret.

Attorneys general have challenged Mr. Trump’s executive order attempting to end birthright citizenship. This week, Ms. James warned New York hospitals that complying with a White House executive order seeking to end gender-affirming medical care for young people could violate state law.

The actions of DOGE — bulldozing through the federal government — have been confounding and concerning to Democratic lawmakers and federal employees.

With license from Mr. Trump, Mr. Musk’s mandate appears to be vast: His team has tried to shut down the U.S. Agency for International Development, a key international source of foreign assistance. On Friday, a federal judge in Washington ordered a pause on an effort to put 2,200 U.S.A.I.D. employees on leave and rapidly withdraw employees stationed abroad.

On Friday, Mr. Trump said that Mr. Musk would turn his attention to the Pentagon, which has billions of dollars in contracts with companies Mr. Musk owns.

The heart of the lawsuit filed by the coalition on Friday was focused on Mr. Musk’s access to the Treasury Department. The department’s system is a repository of some of Americans’ most sensitive information, including Social Security and bank account numbers, which the attorneys general said puts residents of their states at personal risk.

Nathan Willis contributed reporting.