Joe Biden
(Picture: AFP via Getty Images)Joe Biden has warned Ukraine’s president that Russia could invade next month, the White House said.
The Kremlin also said it saw "little ground for optimism" in resolving the crisis after the US again rejected Russia's main demands.
The White House said President Biden's comments to Ukraine's Volodymyr Zelenskyy in a phone call amplified concerns that officials have been making for some time.
"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."
President Biden warned Mr Zelenskyy that the US believed there was a high degree of likelihood Russia could invade when the ground freezes, according to reports.
Russian forces could attack Ukrainian territory from north of Kyiv, Mr Biden is also said to have warned.
The US also announced the UN Security Council will hold an open meeting on Monday on what American officials say is Russia’s "threatening behaviour."
Ambassador to the UN, Linda Thomas-Greenfield, said the deployment of more than 100,000 troops along Ukraine's border poses "a clear threat to international peace and security and the UN Charter."
Russia denies wanting to invade Ukraine and has laid out a series of demands it says will improve security in Europe.
Mr Zelenskyy said on social media that he and President Biden also discussed the possibility of additional financial support for Ukraine.
The White House said Mr Biden was "exploring additional macroeconomic support to help Ukraine's economy" as it comes under pressure as a result of Russia's military build-up.
