Putin has 'made the decision' to invade Ukraine: Biden

US President Joe Biden said he believes Russian leader Vladimir Putin has decided to invade Ukraine and that the attack could begin "in the coming days."

"As of this moment, I'm convinced he's made the decision. We have reason to believe that," Biden said, adding that Washington has "significant intelligence capability" to back the claim.

"We believe they will target Ukraine's capital Kyiv, a city of 2.8 million innocent people," he said of Russian forces.

But with US Secretary of State Antony Blinken scheduled to speak with Russian Foreign Minister Sergei Lavrov on Thursday, Biden said there is still time for negotiations to defuse the crisis.

"Diplomacy is always a possibility," he said.

Biden said Moscow is conducting a disinformation campaign, including accusing Kyiv of planning its own attack in order to create a pretext for a Russian invasion.

"There is simply no evidence to these assertions and it defies basic logic to believe the Ukrainians would choose this moment, with well over 150,000 (Russian) troops arrayed on its borders, to escalate a years-long conflict," Biden said.

"All these are consistent with the playbook the Russians have used before to set up a false justification to act against Ukraine," Biden said at the White House.

US President Joe Biden questioned Friday whether it was a "wise choice" for his Ukrainian counterpart Volodymyr Zelensky to leave the country, after warning a Russian invasion appeared imminent.

"In the pursuit of a diplomatic solution, it may not be, it may be the wise choice. But it's his decision," Biden said during a press conference, when asked about Zelenksy's intention to travel to this weekend's Munich Security Conference.