WASHINGTON (AP) — Russia and Ukraine will “immediately” begin ceasefire negotiations, US President Donald Trump said Monday after separate calls with the leaders of both countries meant to spur progress toward ending the three-year war. The conversations did not appear to yield a major breakthrough.

It was not clear when or where any talks might take place or who would participate. Trump’s announcement came days after the first direct engagement between Russian and Ukrainian delegations since 2022. Those negotiations Friday in Turkey brought about a limited exchange of prisoners, but no pause in the fighting.

Ahead of the calls, the White House said Trump had grown “frustrated” with both leaders over the continuing war. Vice President JD Vance said Trump would press Russian President Vladimir Putin to see if he was truly interested in stopping the fighting, and if not, that the US could disengage from trying to stop the conflict. Trump later told reporters that he believed Putin was serious about wanting peace.

“The conditions for that will be negotiated between the two parties, as it can only be, because they know details of a negotiation that nobody else would be aware of,” Trump said in a social media post.

Trump said the call with Putin was “excellent,” adding, “If it wasn’t, I would say so now, rather than later.”

Later, speaking to reporters in the Oval Office, he noted the process has “got very big egos involved, I tell you.”

“Big egos involved. But I think something’s going to happen and, if it doesn’t I’d just back away and they have to keep going,” Trump said. “This was a European situation. It should have remained a European situation.”

Trump also said he told Putin, “We’ve got to get going.”

Trump has struggled to end a war that began with Russia’s invasion in February 2022, a setback for his promises to quickly settle the conflict once he was back in the White House, if not before he took office.

“He’s grown weary and frustrated with both sides of the conflict,” White House press secretary Karoline Leavitt told reporters Monday before the calls.

The Republican president is banking on the idea that his force of personality and personal history with Putin will be enough to break any impasse over a pause in the fighting. He dangled the prospect of reduced sanctions and increased trade with Russia should the war end.

After the call, Putin said Russia was ready to continue discussing an end to the fighting after a “very informative and very frank” conversation with Trump. Putin said the warring countries should “find compromises that would suit all parties.”

Moscow, he said, will “propose and is ready to work with” Ukraine on a “memorandum” outlining the framework for “a possible future peace treaty.”

But indicating that little had fundamentally changed about his demands, Putin said: “At the same time, I would like to note that, in general, Russia’s position is clear. The main thing for us is to eliminate the root causes of this crisis.”

Ukrainian President Volodymyr Zelensky said Monday that he reaffirmed to Trump that Ukraine is ready for a full and unconditional ceasefire. He urged the international community to maintain pressure on Moscow if it refuses to halt its invasion.

“Ukraine doesn’t need to be persuaded — our representatives are ready to make real decisions. What’s needed is mirrored readiness from Russia for such result-oriented negotiations.” Zelensky said.

Russian presidential adviser Yuri Ushakov, who previously served as Russian ambassador to the US, described the conversation as friendly, with Trump and Putin addressing each other by their first names.

“Trump said, ‘Vladimir, you can pick up the phone at any time, and I will be happy to answer and speak with you,'” he said. Ushakov also said Trump and Putin could meet face-to-face at some point, but no timeline was set.

Putin and Trump also talked about a Russia-US prisoner exchange, which Ushakov said was “in the works” and envisioned Moscow and Washington releasing nine people each. Ushakov did not offer any other details.

Speaking before the call, Vance said Trump could walk away from trying to end the war if he feels Putin isn’t serious about negotiation.

“I’d say we’re more than open to walking away,” Vance told reporters before leaving Rome after meeting with Pope Leo XIV. Vance said Trump has been clear that the US “is not going to spin its wheels here. We want to see outcomes.”

Zelensky, who spoke to Trump one-on-one before the Putin call and then jointly with European leaders after, told reporters that he emphasized to Trump that no decisions should be made about Ukraine without involving Kyiv. He also said that he discussed the potential for “serious sanctions” on Russia.

Trump said the Vatican expressed interest in hosting the negotiations, but there was no immediate confirmation that any talks had been scheduled.

Trump sought to use financial incentives to broker some kind of agreement after Russia’s invasion led to severe sanctions by the United States and its allies that have steadily eroded Moscow’s ability to grow.

“Russia wants to do largescale TRADE with the United States when this catastrophic “bloodbath” is over, and I agree,” he said in a social media post. “There is a tremendous opportunity for Russia to create massive amounts of jobs and wealth. Its potential is UNLIMITED.”

Trump’s treasury secretary, Scott Bessent, said Sunday on NBC’s “Meet the Press” that Trump had made it clear that a failure by Putin to negotiate “in good faith” could lead to additional sanctions against Russia.

Bessent suggested the sanctions that began during the administration of Democratic President Joe Biden were inadequate because they did not stop Russia’s oil revenues, due to concerns that doing so would increase US prices. The United States sought to cap Russia’s oil revenues while preserving the country’s petroleum exports to limit the damage from the inflation that the war produced.

Trump and Zelensky spoke with leaders from France, Italy and Finland, as well as European Commission President Ursula von der Leyen, who have threatened tougher sanctions on Russia in a bid to force Putin into negotiations.

Putin recently rejected an offer by Zelensky to meet in-person in Turkey as an alternative to a 30-day ceasefire urged by Ukraine and its Western allies, including Washington. Instead, Russian and Ukrainian officials met in Istanbul for talks, the first such direct negotiations since March 2022.

Those talks ended Friday after less than two hours, without a ceasefire in place. But both countries committed to exchange 1,000 prisoners of war each, with Ukraine’s intelligence chief, Kyrylo Budanov, saying on Ukrainian television Saturday that the exchanges could happen as early as this week.