WASHINGTON - U.S. President Joe Biden warned Thursday warned Ukrainian President Volodymyr Zelenskiy there is a "distinct possibility" that Russia could invade Ukraine next month, according to a White House statement.

"President Biden said that there is a distinct possibility that the Russians could invade Ukraine in February," Emily Horne, the White House National Security Council spokesperson said. "He has said this publicly, and we have been warning about this for months."

Russia said Thursday there was "little ground for optimism" that tensions would ease in Eastern Europe after the United States rejected its demand that Ukraine be banned from NATO membership and that the West pull back its troop deployment and weaponry from countries bordering Russia.

Russian Foreign Minister Sergey Lavrov said the U.S. reply to its demands "contains no positive response," but that some elements of it could lead to 'the start of a serious talk on secondary issues.' The U.S. and its European allies have rejected the key Moscow demands as nonstarters.

The top Kremlin diplomat said officials will submit proposals to President Vladimir Putin. His spokesperson, Dmitry Peskov, said the Russian reaction would come soon, adding that "there always are prospects for continuing a dialogue. It's in the interests of both us and the Americans.'

Biden talked Thursday with President Zelenskiy to reassure him of U.S. and allied support during the mounting tension. Afterward, the Ukrainian leader tweeted that he and Biden had also talked about additional financial support for Ukraine.

Ukraine: What We Know 

Officials from Ukraine, Russia, France and Germany held talks Wednesday in Paris and agreed to another round of talks in Berlin in the second week of February. The sides agreed to maintain an official cease-fire in eastern Ukraine, according to Dmitry Kozak, the Kremlin's envoy.

'We need a supplementary pause. We hope that this process will have results in two weeks,' he said.

The February talks will take place at the same diplomatic level as the Paris talks. Not on the agenda is a summit with heads of state.

"Nothing has changed, this is the bad news," Ukrainian Foreign Minister Dmytro Kuleba said. "The good news is that advisers agreed to meet in Berlin in two weeks, which means that Russia for the next two weeks is likely to remain on the diplomatic track."

The U.S. has called for a meeting Monday of the United Nations Security Council on Ukraine.

'More than 100,000 Russian troops are deployed on the Ukrainian border and Russia is engaging in other destabilizing acts aimed at Ukraine, posing a clear threat to international peace and security and the U.N. Charter,' U.S. Ambassador to the U.N. Linda Thomas-Greenfield said Thursday in a statement. "This is not a moment to wait and see. The Council's full attention is needed now, and we look forward to direct and purposeful discussion on Monday."

Russia is one of the five permanent members of the Security Council and therefore has veto power over any resolution.

The meeting, Thomas-Greenfield said, will be about exposing Russia for its actions and isolating the Kremlin for its aggressive posture regarding Ukraine, according to Agence France-Presse.

Embed share Russia Says It's Ready for More Talks on Ukraine Embed share The code has been copied to your clipboard. width px height px

• Share on Facebook
• Share on Twitter

No media source currently available

0:00 0:02:54 0:00

The U.S. and its European allies, fearing an imminent Russian invasion of Ukraine, continue to protest Russia's massing of more than 100,000 troops along its border with the onetime Soviet republic, although Moscow says it has no intention of attacking.

Secretary of State Antony Blinken said the document the U.S. handed Russia "includes concerns of the United States and our allies and partners about Russia's actions that undermine security - a principled and pragmatic evaluation of the concerns that Russia has raised, and our own proposals for areas where we may be able to find common ground."

Biden, while ruling out sending U.S. troops to Ukraine, repeatedly has warned Russia that the West will impose crippling economic sanctions against it if it crosses the border and attacks Ukraine.

While Russia and the U.S. and its allies trade demands, both sides have ramped up military preparations. Russia has launched military drills involving motorized infantry and artillery units in southwestern Russia, warplanes in Kaliningrad on the Baltic Sea, dozens of warships in the Black Sea and the Arctic, and Russian fighter jets and paratroopers in Belarus.

NATO said it was boosting its presence in the Baltic Sea region, and the U.S. has put 8,500 troops on heightened alert for deployment to Europe as part of a NATO operation.

Pentagon press secretary John Kirby said American forces currently in Europe, some already on heightened alert, could likewise be mobilized "to also bolster our NATO allies if they need that.

Kuleba said Ukraine is not planning any offensive actions, and he expects diplomatic efforts to address the crisis along the Russia-Ukraine border to continue.

"We are committed to [a] diplomatic track, and we are ready to engage with Russia at different levels in order to find [a] diplomatic solution to the conflict," Kuleba said at a news conference. "However, if Russia decides to fight, we will fight back. This is our country, and we will defend it.'

Some information for this report came from The Associated Press, Deutsche Welle, Agence France-Presse, and France 24.