Officials said there have been no specific threats to British diplomats, but about half of the staff working in Kyiv will return to the UK, BBC reported.

It comes as the US ordered the relatives of its embassy staff to leave Ukraine, saying a Russian invasion could come at any time, while Russia has denied having any plans for military action in Ukraine.

However, the move is a precautionary one, and nothing specific is thought to have occurred in the past 24 hours to have triggered the decision.

Non-essential US embassy staff have also been told they can leave, and US citizens have been told to do the same.

The European Union will not be doing the same at the moment. EU Security Policy chief Josep Borrell said he will not dramatize the tensions.

Ukraine and the United States have repeatedly claimed that Russia is seeking to invade Ukraine, but Russian officials have repeatedly described these allegations as baseless.

MP/PR