Britons are being advised against all travel to Ukraine and those already in the country are being told to leave while they can.
The action came as Boris Johnson told world leaders he “feared for the security of Europe” over the threat of a Russian invasion of Ukraine.
And the White House on Friday stated its belief that Russian military aggression against its neighbour could begin “any day now” – including during the current Winter Olympics, which are scheduled to end on 20 February.
‘British nationals in Ukraine should leave now’
On Friday evening, the Foreign Office issued updated travel guidance to advise UK citizens “against all travel to Ukraine”.
“British nationals in Ukraine should leave now while commercial means are still available,” the updated advice added.
“Since January 2022, the build-up of Russian forces on Ukraine’s borders has increased the threat of military action.
“Due to this increased threat, the FCDO has taken the decision to further withdraw embassy staff from Kyiv.
“The embassy remains open but will be unable to provide in-person consular assistance. British nationals should leave while commercial options remain.”
The action copies that taken by the US government, who were already advising Americans against travelling to Ukraine due to “the increased threats of Russian military action”.
The State Department is also urging all those US citizens currently in Ukraine to leave the country now.
PM tells allies he ‘fears for security of Europe’
In a virtual meeting on Friday evening, the prime minister spoke with the leaders of the US, Italy, Poland, Romania, France, Germany, the EU, and NATO.
“The prime minister told the group that he feared for the security of Europe in the current circumstances,” a Downing Street spokesperson said.
“He impressed the need for NATO allies to make it absolutely clear that there will be a heavy package of economic sanctions ready to go, should Russia make the devastating and destructive decision to invade Ukraine.
“The prime minister added that President [Vladimir] Putin had to understand that there would be severe penalties that would be extremely damaging to Russia’s economy, and that allies needed to continue with efforts to reinforce and support the Eastern frontiers of NATO.
“He urged the leaders to work together to deliver economic and defensive support to Ukraine.”
But the spokesperson added that world leaders had agreed, if Mr Putin “deescalated”, there would be “another way forward” as they “pledged to redouble diplomatic efforts in the coming days”.
White House warns Russian invasion could begin ‘any day now’
After the virtual meeting between Mr Johnson, US President Joe Biden and other world leaders, White House national security adviser Jake Sullivan said Russia now had enough forces to conduct a major military operation against Ukraine.
An assault could begin “any day now” and “could occur before the Olympics have ended”, Mr Sullivan told a televised briefing as he urged any American still in Ukraine to leave in the next 24-48 hours.
“The risk is high enough and the threat is now immediate enough that prudence demands that it is the time to leave now,” he said.
“We are not saying that a decision has been taken by President Putin.
“What we are saying is that we have a sufficient level of concern based on what we are seeing on the ground, and what our intelligence analysts have picked up, that we are sending this clear message.”
Russia is currently holding massive war games in Belarus, which borders Russia, Ukraine and Poland.
UK-Russia relations ‘above zero’
Earlier in the day, Defence Secretary Ben Wallace had continued those diplomatic efforts as he held talks with his Russian counterpart in Moscow.
Mr Wallace described the discussions as “constructive and frank” and said that relations between Russia and Britain were “above zero” following the first meeting between a UK defence minister and Russia’s Sergei Shoigu since 2013.
Stressing the need for talks to prevent “miscalculation and escalation”, Mr Wallace expressed his hope that Friday’s meeting had contributed to a “better atmosphere” between the two sides.
“When they say to me they are not going to invade Ukraine we will take that seriously but, as I also said, we will look at the actions that accompany it,” the defence secretary said.
Mr Wallace also agreed with a US assessment that a Russian invasion of Ukraine could happen “at any time”, amid the ongoing joint military drills between Russia and Belarus.
“The disposition of the Russian forces that we see – over 100,000 in both Belarus and Ukraine – obviously gives that size of force the ability to do a whole range of actions, including an invasion of a neighbouring country at any time,” he said.
“We obviously have made it very clear in NATO that an invasion would have tragic consequences and we are here, and I’m here today for example, to seek a way of whatever we can to deescalate that tension.
“I heard clearly from the Russian government that they had no intention of invading Ukraine. And I also heard some of their concerns.”