Boris Johnson has warned that Russia faces “disaster” if President Vladimir Putin makes any sort of incursion into Ukraine.

Speaking during a visit to a diagnostics centre in Taunton, the Prime Minister reiterated the UK’s support for Ukrainian sovereignty.

“If Russia were to make any kind of incursion into Ukraine on any scale whatever I think that would be a disaster for not just for Russia, it would be a disaster for the world,” he said.

“The UK stands squarely behind the sovereignty and integrity of Ukraine.”

His comments came after US President Joe Biden said he did not believe Mr Putin wanted a full blown war, and would pay a “dear price” if he did mount a military incursion against Russia’s neighbour.

Speaking at a news conference to mark his one-year anniversary in office, Mr Biden said he believed Russia was preparing to take action, although he did not think Mr Putin had made a final decision.

He suggested that the US would limit Russia’s access to the international banking system if it did further invade Ukraine.

On a visit to Kiev, US Secretary of State Antony Blinken accused Moscow of planning to reinforce the more than 100,000 troops it has deployed along the Ukrainian border suggesting the numbers could double “on relatively short order”.

Mr Johnson and German Chancellor Olaf Scholz “shared their deep concern at the ongoing destabilising action by Russia in Ukraine” in a call on Thursday evening, a Downing Street spokesperson said.

They added that the pair said “any invasion into Ukraine would be a severe strategic mistake”.

Russian president Vladimir Putin (Matt Cardy/PA)
Vladimir Putin (Matt Cardy/PA)

“The Prime Minister spoke to German Chancellor Olaf Scholz this evening about the situation in Ukraine,” the spokesperson said.

“The leaders discussed the concerning developments on the Ukrainian border, and agreed further military aggression would come at a high cost for Russia.

“They shared their deep concern at the ongoing destabilising action by Russia in Ukraine, and said any invasion into Ukraine would be a severe strategic mistake.

“The Prime Minister stressed the importance of Nato allies working together on a co-ordinated response.

“The leaders agreed to stay in close contact on the issue, and the Prime Minister said he looked forward to working closely with Chancellor Scholz throughout their G7 presidency.”