INVADING Ukraine would be a "crime against humanity", according to Ian Blackford as he called for diplomatic solutions to the crisis. 

He said the UK “can’t stand back” if Russia invades Ukraine as he called for the “highest level” of sanctions in the event of war.

The SNP Westminster leader urged for the “hand of friendship” to be extended to the Russian people while saying the country’s leaders had to fall in line with the “rule of law”.

Invading Ukraine would be a “crime against humanity”, Blackford told Sky News on Monday morning.

And Western leaders had a duty to push for peaceful solutions to the crisis in Eastern Europe, he said.

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He added: “All of us across the West must stand together and use every minute of every day to strive for diplomatic solutions.

“We must say to Russia, President Putin and his supporters, that they must draw back.

“This is a worrying moment and the potential threat of an incursion of Russian troops in Ukraine almost doesn’t bear thinking about in terms of the consequences of that and what that would mean for the Ukrainian people.

“We must absolutely reiterate that we stand with them. But there will be a very direct response to Russia if they do invade Ukraine.”

He noted the West’s “deep love” for the Russian people – recalling when British and American fought against Axis powers with Soviet troops in the Second World War.

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But the “behaviour of the regime”, including its military aggression and poisoning of Sergei and Yulia Skripal in Salisbury, Wiltshire in 2018, was branded "unacceptable".

Blackford added: “Russia has to come into the world order and they must recognise that what they are doing now is not a way they can win friends and influence and be part of that world order.

“It has to be about democratic states and one that recognises the rule of law.”

His comments come as world leaders ramp up efforts to discourage Russia from invading its neighbour.

Boris Johnson will travel to Europe later this week as part of intensive diplomatic efforts to bring Russian President Vladimir Putin “back from the brink” of war in Ukraine.

The Prime Minister, Defence Secretary Ben Wallace and Foreign Secretary Liz Truss are all due to take part in meetings with international counterparts to discuss the crisis.

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But there were acknowledgements in Whitehall diplomacy may prove futile if the Kremlin is set on war.

The diplomatic activity came as the UK stepped up warnings for Britons to evacuate from Ukraine, with a defence minister suggesting missiles would start raining down on the country within minutes of Putin deciding to launch an invasion.

Downing Street conceded Moscow could be planning to invade “at any moment” but the Prime Minister will hold talks with world leaders before a trip to Europe during this week’s “window of opportunity” for de-escalation.