Warsaw, Poland - US President Donald Trump backs a Russian proposal for Moscow to take full control of two Ukrainian regions and freeze the front line in two others, which Moscow only partially controls, a source told AFP.

The source with knowledge of the matter said Russian President Vladimir Putin "de facto demands that Ukraine leave Donbas," an area consisting of the Donetsk and Lugansk regions in eastern Ukraine.

"Trump is inclined to support it," the source said.

Trump on Saturday spoke to Ukrainian President Volodymyr Zelensky and European leaders about his talks Friday with Russian President Vladimir Putin.

Donald Trump Trump administration to shed hundreds of thousands of government workers in 2025, forecasts reveal

Politicians Gavin Newsom unveils redrawn California district map while mocking Trump's "tiny hands"

"The Ukrainian president refused to leave Donbas," the source said.

Zelensky has rejected any territorial concessions, saying he is bound by Ukraine's constitution. But he has not ruled out discussing the issue at a trilateral meeting with Trump and Putin.

The New York Times also cited two senior European officials saying Trump supported Putin's plan "to end the war in Ukraine by ceding unconquered territory to the Russian invaders, rather than try for a ceasefire."

The Financial Times reported that Putin had told Trump that "he could freeze the rest of the frontline if his core demands were met," and the message had been relayed directly by Trump in his call on Saturday.

AFP's source said US officials had said that if Russia's demands were met, then "Putin would not continue the offensive in the Kherson and Zaporizhzhia regions so there would be a kind of freeze there... But de facto it all will depend on Putin's word of honor."

Several months into its invasion of Ukraine, Russia in September 2022 claimed to have annexed all four Ukrainian regions, even though its troops still do not fully control any of them.

Russian forces now occupy almost all of the Lugansk region and most of the Donetsk region, including their regional capitals.

That is not the case for Zaporizhzhia and Kherson, where the main hubs are still under Ukrainian control. Russia previously annexed the Crimean peninsula from Ukraine in 2014.