U.S. President Joe Biden on Sunday told Ukraine's President Volodymyr Zelenskiy the United States and its allies will "respond decisively" if Russia further invades Ukraine, the White House said in a statement.
The call came days after Biden held a second conversation in a month with Russian President Vladimir Putin amid tensions on Russia's border with Ukraine, where Russia has massed some 100,000 troops.
"President Biden made clear that the United States and its allies and partners will respond decisively if Russia further invades Ukraine," White House spokesperson Jen Psaki said in a statement following the call.
Ukrainian President Zelenskiy said he discussed with President Biden joint actions on keeping peace in Europe and preventing further escalation.
"The first international talk of the year with @POTUS proves the special nature of our relations," Zelenskiy wrote on Twitter. He said the joint actions of Ukraine, the United States "and partners in keeping peace in Europe, preventing further escalation, reforms, deoligarchization were discussed. We appreciate the unwavering support of Ukraine."
Last week Presidents Joe Biden and Vladimir Putin spoke about the Russian troop build-up near Ukraine during their second call in recent weeks.
U.S. President Joe Biden holds virtual talks with Russia's President Vladimir Putin amid Western fears that Moscow plans to attack Ukraine.
The White House
Mr Putin’s foreign affairs adviser said Mr Biden reaffirmed the US threat of new sanctions against Russia in case of an escalation or invasion, to which Mr Putin responded with a warning that such a move could lead to a complete rupture of ties.
“It would be a colossal mistake that would entail grave consequences,” said Yuri Ushakov. He added that Mr Putin told Mr Biden that Russia would act as the US would if offensive weapons were deployed near American borders.
Ahead of the 50-minute conversation on Thursday, the White House indicated that Mr Biden would make clear to Mr Putin that a diplomatic path remains open even as the Russians have moved an estimated 100,000 troops towards Ukraine and Mr Putin has stepped up his demands for security guarantees in Eastern Europe.
But Mr Biden would reiterate to Mr Putin that for there to be “real progress” in talks they must be conducted in “a context of de-escalation rather than escalation”, according to a senior administration official.
The call, which was requested by Russian officials, comes as senior US and Russian officials are to hold talks on January 10 in Geneva.