Biden speaks with Zelenskiy, repeats strong warning to Russia

The White House statement said the two leaders also discussed diplomatic efforts to ease tensions following a large-scale buildup of Russian military presence along Ukraine's eastern border.

The two presidents also discussed measures to "reduce tensions in Donbas as well as develop active diplomacy to move forward with the implementation of the Minsk agreements."

President Biden “reaffirmed the United States’ commitment to the sovereignty and territorial integrity of Ukraine,” the White House statement said, adding that Mr. Biden emphasized Washington’s commitment to the principle of “nothing for you, without you” (a formula used to communicate the idea that no decision should be made without the full and direct participation of the country affected by the decision).

In a tweet, Mr. Zelenskiy wrote that the two leaders discussed "joint actions in cooperation with partners to preserve peace in Europe, prevent further escalation of the situation, carry out reforms, and root out the oligarchs."

"We appreciate the unwavering support for Ukraine," Mr. Zelenskiy said.

During his call with Russian President Vladimir Putin, President Biden made little progress in getting him to withdraw about 100,000 troops stationed along Russia's border with the former Soviet republic. However, American officials say they do not believe Moscow has decided to attack Kiev.

The U.S. and Russian leaders held a 50-minute phone call last Thursday, during which Mr. Biden again warned Mr. Putin that the United States and its Western allies would impose strong economic sanctions on Moscow if it attacked Ukraine. Mr. Biden said last month that he was not considering a military response to the rising tensions.

Moscow annexed Ukraine's Crimean Peninsula in 2014, despite criticism from the West, which imposed sanctions that were less severe than those it has currently pledged to take in the event of a new attack.