Britons have been told to leave Ukraine immediately over concerns of a possible invasion by Russian forces.
The Foreign Office updated its advice on Friday evening to tell UK nationals to “leave now while commercial means are still available”.
The warning came after Boris Johnson voiced fears for the security of Europe during a call with world leaders including US President Joe Biden.
A Foreign Office spokesman said: “The safety and security of British nationals is our top priority, which is why we have updated our travel advice.
“We urge British nationals in Ukraine to leave now via commercial means while they remain available.”
Boris Johnson told world leaders that he fears for the security of Europe, according to Downing Street.
After a virtual call, a No 10 spokesman said: “The Prime Minister told the group that he feared for the security of Europe in the current circumstances.
“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 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.
“The leaders agreed that if President Putin deescalated, there was another way forward, and they pledged to redouble diplomatic efforts in the coming days.”