Ukrainian President Volodymyr Zelenskiy said he thanked Washington for the initiative, which he described as halting Russian strikes on energy targets, which have left hundreds of apartments in Kyiv without power during freezing weather.

There was no immediate comment from Moscow, which had earlier issued a new invitation for Zelenskiy to hold talks in Moscow, an offer already long rejected by the Ukrainian leader.

"We asked President Putin if they could stop the shooting for a week," Trump told reporters at an event in the Oval office.

"They're being hit with, proportionately, the kind of cold that we're being hit. It's much colder in Ukraine to start off with, but it's really cold. He agreed to do that. We appreciated that very much."

Emergency crews were still restoring heating and electricity in Kyiv knocked out by Russian air strikes last Saturday.

Kyiv Mayor Vitaly Klitschko said 454 apartment buildings remained without heat, with overnight temperatures dipping to -10 Celsius (18 Fahrenheit) on Friday and even lower next week.

"We expect the agreements to be implemented," Zelenskiy wrote on the X social media platform. "De-escalation steps contribute to real progress toward ending the war."

Speaking afterwards in his nightly video address, Zelenskiy thanked the United States "for their efforts in ensuring a stop to strikes on energy (targets) at this time and let's hope that America succeeds in ensuring this".

"We shall see what the real situation is with our energy facilities and cities in the days and nights to come," he said.

The United States has been engaged in months of diplomatic activity to secure an accord to end the nearly four-year-old war, the deadliest conflict in Europe since World War Two.

Negotiators from Ukraine, Russia and the United States held unusual three-way contacts last weekend in the United Arab Emirates.

Trump's envoy Steve Witkoff said on Thursday the Russia and Ukraine were discussing the issue of territory and described the talks as having made progress. He said accords on security guarantees and post-war recovery were nearly complete.

Ukraine is resisting Russia's demands to cede all its eastern Donbas region, including areas Moscow's military has failed to capture.

Kremlin aide Yuri Ushakov said he did not regard the land issue as the only key matter left on the table.

Witkoff said the discussions would resume in about a week, though the next meeting had been scheduled for Sunday.

Russian Foreign Minister Sergei Lavrov cast doubt on the viability of any security guarantees that Washington might be able to provide Ukraine as part of a deal. He expressed doubt that they could lead to an enduring peace if they were designed to keep Ukraine's current political leadership in power.