US President Joe Biden has warned there is a “distinct possibility” Russia might invade Ukraine next month, the White House says.
Russia meanwhile says it sees “little ground for optimism” in resolving the crisis after the US rejected Russia’s main demands.
The build-up of tens of thousands of Russian troops on Ukraine’s borders in recent weeks has stoked fears of an invasion.
Russia denies it is planning an attack.
The US president made the comments in a telephone conversation with Ukrainian President Volodymyr Zelensky on Thursday.
“President Biden said that there is a distinct possibility that the Russians could invade Ukraine in February,” White House National Security Council spokesperson Emily Horne said.
“He has said this publicly and we have been warning about this for months.”
During their talk, President Biden “reaffirmed the readiness of the United States along with its allies and partners to respond decisively if Russia further invades Ukraine”, a White House statement said.
Mr Zelensky said they “discussed recent diplomatic efforts on de-escalation and agreed on joint actions for the future”.
Axios, citing unnamed sources, suggested the two disagreed on how imminent the threat was. Some military experts suggest Russia may be waiting for the ground in Ukraine to freeze so they can move in heavy equipment.
U.S. asks U.N. Security Council to meet on Russia, Ukraine
Meanwhile, the United States has asked that the United Nations Security Council meet publicly on Monday to discuss Russia’s “threatening behavior” against Ukraine and its troop build-up on Ukraine’s borders and in Belarus, the U.S. Ambassador to the United Nations said on Thursday.
Russia has massed around 100,000 troops near the border with Ukraine while denying it plans to invade. Several rounds of talks have taken place without a breakthrough but both the U.S.-led NATO military alliance and Russia have kept the door open to further dialogue.
“Russia is engaging in other destabilizing acts aimed at Ukraine, posing a clear threat to international peace and security and the U.N. Charter,” ambassador Linda Thomas-Greenfield said 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,” she said.
Any Security Council member could call for a procedural vote to block the meeting. A minimum of nine votes are needed to win such a vote and China, Russia, the United States, Britain and France cannot wield their vetoes. U.N. diplomats said any attempt to stop the meeting on Monday would likely be defeated.
The U.N. Security Council has met dozens of times over the crisis in Ukraine since Russia annexed Crimea in 2014. It is unable to take any action as Russia is one of the council’s five veto powers.
“As we continue our relentless pursuit of diplomacy to de-escalate tensions in the face of this serious threat to European and global peace and security, the U.N. Security Council is a crucial venue for diplomacy,” Thomas-Greenfield said.
Photo – A frame grab taken from a handout video made available by the Russian Defence Ministry Press Service shows Russian servicemen from the units of the 150th Motor Rifle Division of the Southern Military District taking part in exercises on the training grounds in the Rostov Region, Russia. About 3,000 servicemen of the Guards Red Banner Combined Arms Army of the Western Military District (ZVO) have begun combat training at training grounds in the regions of Rostov, Krasnodar, Yaroslav, Voronezh, Belgorod, Bryansk and Smolensk. EPA-EFE/RUSSIAN DEFENCE MINISTRY PRESS SERVICE HANDOUT —
