The UK defence secretary has admitted he is "not optimistic" that Russian president Vladimir Putin can be persuaded against invading Ukraine as the prospect of war between the neighbouring countries grows increasingly likely.
Ben Wallace has travelled to Europe to engage with the leaders there about the crisis and to drum up support for sanctions against the Kremlin as Moscow continues to build up its military presence on the border.
Prime minister Boris Johnson said earlier this week that the UK would send troops to its allies in eastern Europe should Moscow press ahead with an invasion in the coming days or weeks.
Russia denies it is planning an invasion.
On Wednesday night Joe Biden's White House issued its first written response to Russia, which is demanding that Nato will not grow any further east, citing security concerns. Moscow is also seeking assurances that Ukraine will never be allowed to join the military alliance.
The US is said to want reassurances from the UK that it would help reinforce Nato’s eastern flank, from the Baltic states to Romania and Bulgaria in the south, by bolstering military presence. Reports say British military officials are in advanced talks about how to respond to the request.
Mr Wallace has confirmed he will head for Moscow to speak with Sergei Shoigu, Russia's defence minister, once he has finished talks with leaders in Europe.
Before making the trip east, he told the BBC that the prospect of a Russian invasion looks increasingly likely. There is still "a chance" that Russia could be stopped, although he warned: "I'm not optimistic".
It comes after Liz Truss, the foreign secretary, said the UK is not ruling out support for personal sanctions against Mr Putin in the event of a Russian invasion.
Ms Truss made the comments after President Biden suggested that moving to penalise the Russian president could be an option in the event of war.
When asked on Tuesday if he could see himself sanctioning Mr Putin in those circumstances, Mr Biden told reporters: "Yes, I would see that."
Asked if the UK would support personal sanctions against the Russian president, Ms Truss told BBC Radio 4's Today programme on Wednesday that the Government had "ruled nothing out".
"We have ruled nothing out in terms of sanctions, and in fact we'll be legislating to toughen up our sanctions regime and make sure we are fully able to hit both individuals and companies, and banks, in Russia in the event of an incursion," she said.
"What's important is that all of our allies do the same, because it's by collective action, by showing Vladimir Putin we're united, that we will help deter a Russian incursion."
Russia has also been amassing troops in Belarus where they have been conducting military exercises. The Belarusian Ministry of Defence said on Thursday that the soldiers would leave once the drills are finished.
The deployments to Belarus, north of Ukraine and an ally of Russia, are part of a wider military buildup in the region. "At the end of the inspection, military units and sub-units of the Russian Federation's Armed Forces will leave the territory of the Republic of Belarus," the ministry said.
The Russian rouble, which has been under serious pressure during the Russian troop buildup, was up 1.1 per cent on Thursday after the statement.
The Allied Resolve exercises are split into two phases and are due to run until 20 Feb.
Additional reporting by agencies
