Ukraine tensions: Biden and Putin phone call seeks 'diplomatic path'

US President Joe Biden is set to hold talks with Russia's Vladimir Putin for the second time this month, in a bid to de-escalate tensions over Ukraine.

They will speak by phone on Thursday.

Mr Biden will offer his Russian counterpart a "diplomatic path" but remains "gravely" concerned by the Russian troop build-up on the border with Ukraine, a US official told AFP news agency.

Russia has denied planning to invade Ukraine.

Moscow says the border troops are there for military exercises, and that Russia is entitled to move its troops freely on its own soil.

The US has consulted European leaders ahead of the call to co-ordinate a common response to the issue, a White House statement said.

Ukrainian security officials say more than 100,000 Russian troops have been sent close to their shared border, and the US has threatened Mr Putin with sanctions "like none he's ever seen" if Ukraine comes under attack.

Mr Biden is expected to tell Mr Putin that the US is prepared to respond if Russia advances with "a further invasion of Ukraine".

Earlier this month, the two presidents held a virtual summit in which Mr Biden reiterated his support for Ukraine's sovereignty and territorial integrity.

While Ukraine is not a Nato member, it has close ties with the bloc.

Russia has said it wants legally binding guarantees that Nato will not move eastwards and that weapons will not be sent to Ukraine or any neighbouring countries.

Nato Secretary-General Jens Stoltenberg has been adamant that Ukraine's membership of the alliance is a matter for Nato and Kyiv. "Any dialogue with Russia has of course to respect the core principles which European security has been based on," he previously said.

Lithuanian President Gitanas Nauseda has described the current situation as probably "the most dangerous it's been in 30 years".

Russian officials are due to meet US counterparts in Geneva on 10 January. Asked earlier this week if he would meet Mr Putin on that date, Mr Biden replied "We'll see", but he is not expected to attend the talks in Geneva.