How a Call From Trump Ignited a Frantic Week of Diplomacy by Ukraine

President Volodymyr Zelensky of Ukraine was returning from the frontline last week when he joined a pivotal call with President Trump.

Hours earlier, Mr. Zelensky had visited soldiers defending Ukraine’s northeastern Sumy region against Russian ground assaults. Now, stopping in the small city of Romny, he listened on a secure line with other European leaders as Mr. Trump outlined Russia’s proposal to end the war.

Moscow, Mr. Trump told them, was ready to halt hostilities under a deal involving a territorial exchange between Russia and Ukraine, according to a Kyiv-based European diplomat and a top Ukrainian official who were briefed on the call and spoke on the condition of anonymity to discuss sensitive information. Seeing a chance to broker peace, Mr. Trump told those on the line that he would meet one on one with President Vladimir V. Putin of Russia to try to seal an agreement.

Mr. Trump had just brought into play two of Kyiv’s deepest fears: that it would be forced to cede land to Russia as part of a peace deal, and that Mr. Putin would be given a way out of his diplomatic isolation. It was a direct challenge to Ukraine’s core principles that territorial issues be addressed only after a cease-fire and that no deal be concluded without Kyiv.

After Mr. Zelensky left the call, he recorded his usual evening address to Ukrainians, trying to project optimism. “I spoke with President Trump,” he said, speaking from a playground in Romny as the sun set behind him. “Russia now seems to be more inclined toward a cease-fire — the pressure is working.”

But, he cautioned, “the key is to ensure they don’t deceive anyone in the details — neither us, nor the United States.”

What followed was a week of frantic diplomacy as Ukraine scrambled to avoid being sidelined in the negotiations and prevent Russia from dictating the terms of peace talks. Mr. Zelensky spoke with nearly 30 world leaders, while his top advisers met online and in person with senior European and American officials to press their case.

In doing so, Ukraine turned to a tactic honed over more than three years of war: rallying partners through repeated behind-the-scenes calls and meetings to keep a seat at the negotiating table. Crucially, Kyiv leaned heavily on its European allies to form a united front and relay its message to the Trump administration.

“The goal was to build a common position with the Europeans and a way to communicate it to Trump,” Oleksandr Kraiev, the director of the North America program at the Kyiv research group Ukrainian Prism, said in an interview. “The Europeans have been really useful in helping Ukraine get back to the table.”

Ukraine’s first task was to determine exactly what Moscow had proposed to end the war. Mr. Trump had been vague on the call, the officials briefed on it said, leaving it unclear which territories might be swapped. Would it involve large areas such as the Ukrainian-controlled part of the eastern Donbas region for Russian-occupied land in the south, or smaller, strategic sites like the Russian-held Zaporizhzhia nuclear plant for a Ukrainian city?

Mr. Zelensky instructed his top aides to clarify the situation. They got on a call last Thursday with European counterparts and Steve Witkoff, Mr. Trump’s special envoy for peace missions, who had received Moscow’s proposal during a meeting with Mr. Putin in Moscow last week. But Mr. Witkoff’s explanations were muddled, according to the Kyiv-based European diplomat, prompting another call the next day to clear up the confusion.

After that second call, it became clear that Moscow was not actually offering to relinquish any land, but only demanding that Kyiv give up the territory it holds in the Donbas in exchange for a cease-fire that would freeze the current frontlines elsewhere.

The Russian proposal was a nonstarter for Ukraine, and Kyiv moved to convince the Americans that it was a dangerous gambit. If Russia took all of the Donbas, Ukrainian officials argued, it would gain control of cities and fortifications forming Ukraine’s main defensive belt in the area. That would put the Russian Army in a much stronger position to attack nearby regions should it decide to resume the war.

At first, Kyiv kept Russia’s proposal under wraps, worried about how Ukrainians would react, said Mr. Kraiev, the Ukraine researcher. Most Ukrainians oppose giving up any territory not already under Russian control or formally recognizing Moscow’s occupation.

“It’s a classic diplomacy rule: If a possible peace treaty is not acceptable to your public, you limit your comments — you don’t say anything,” Mr. Kraeiv said.

But after Mr. Trump disclosed on Friday that a peace deal could include “some swapping of territories,” Mr. Zelensky had little choice but to push back. “Ukrainians will not gift their land to the occupier,” he said Saturday morning.

Mr. Zelensky, however, appears to have not entirely ruled out possible territorial exchanges, telling reporters this week that this is “a very complex issue that cannot be separated from security guarantees for Ukraine.”

To bolster its stance with the Americans, Ukraine continued to enlist its European allies. Over the past week, Mr. Zelensky spoke by phone with more than 20 European leaders, including several times with President Emmanuel Macron of France, a close ally.

The intense week of diplomacy culminated in a joint call between European leaders, Mr. Zelensky and Mr. Trump on Wednesday, exactly a week after Mr. Trump first revealed Russia’s peace proposal. European leaders reiterated their key principles: that a cease-fire must come first; that the current frontlines should be the starting point for any negotiations, including on territorial issues; and that any deal would have to be accompanied by security guarantees for Kyiv.

The top Ukrainian official said the Americans had carefully listened to Ukraine’s and Europe’s arguments throughout the week, but he cautioned that no one really knew what they had in mind ahead of Friday’s meeting.

Mr. Zelensky echoed that sentiment on Tuesday. “I don’t know what they will talk about without us,” he told reporters. But he stressed that “substantive and productive talks about us without us will not work.”