
Evidence suggests Russia is planning “the biggest war in Europe since 1945”, said British Prime Minister Boris Johnson.
“All the signs are that the plan has already in some senses begun,” Johnson told BBC.
Intelligence suggests Russia intends to launch an invasion that will encircle Ukrainian capital Kyiv, Mr Johnson said.
“People need to understand the sheer cost in human life that could entail,” he said.
The latest estimates by the US government suggests that between 169,000 and 190,000 Russian troops are stationed along Ukraine’s border, both in Russia and neighbouring Belarus – but this figure also includes rebels in eastern Ukraine.
Mr Johnson warned that any conflict could be “bloody and protracted”, saying Russian President Vladimir Putin was possibly “thinking illogically about this” and did not “see the disaster ahead”.
“I think it’s vital for us all now to get over what a catastrophe it would be for Russia,” he added.
An invasion of Ukraine would strengthen, rather than weaken, NATO, he predicted, saying Western countries could not allow opposition forces to come to “the false conclusion that might is right”.
Western nations have accused Russia of trying to stage a fake crisis on Ukraine’s border, warning in recent weeks Mr Putin’s forces could be preparing to invade at any time.
But Russia has denied the claims, saying the massed troops are just conducting military exercises.
Asked whether a Russian invasion was still thought to be imminent, Mr Johnson said: “I’m afraid that that is what the evidence points to. There’s no burnishing it.”