The West must not be cowed by Vladimir Putin, the head of Britain’s Armed Forces has warned ahead of Donald Trump’s high-stakes meeting with the Russian president.

Admiral Sir Tony Radakin said Nato allies must be “assertive in every domain – nuclear, land, sea, air, cyber and space – as well as in the diplomatic and economic arenas” as he cautioned against submitting to Moscow’s demands for peace reports The Telegraph.

The rare intervention by Britain’s most senior military officer comes ahead of Mr Trump’s one-to-one meeting with Putin in Alaska on Friday, which is expected to forge the conditions for peace in Ukraine. The interview comes on the same day it was reported that Putin is tipped to push Trump for European missile concessions at crunch summit.

On Thursday night, Mr Trump said that Putin would not “mess around with me” and threatened to impose further sanctions if he failed to offer a meaningful resolution to the war.

He said he would know “in the first two minutes... exactly whether or not a deal can be made”.

Speaking in the Oval Office on Thursday, he said: “I want to set the table for the next meeting. I’d like to see it happen very quickly.

“We’re going to find out where everyone stands. If it’s a bad meeting, it will end very quickly, and if it’s a good meeting, we will end up having peace in the very near future.”

Putin 'would lose' WW3

European leaders have become increasingly concerned that the pair could negotiate an end to the three-year conflict over Volodymyr Zelensky’s head, but Mr Trump appeared to allay some of those fears on Thursday night.

“The more important meeting will be the second meeting that we’re having, we’re going to have a meeting with President Putin, President Zelensky, myself and maybe we’ll bring some of the European leaders, maybe not,” he said.

“The second meeting is going to be very, very important, because that’s going to be a meeting where they make a deal. And I don’t want to use the word ‘divvy’ things up. But you know, to a certain extent, it’s not a bad term.”

Writing for The Telegraph to mark the 80th anniversary of VJ Day, Sir Tony emphasised the ongoing importance of the Nato alliance born out of the end of the Second World War.

He said: “Putin doesn’t want a war with Nato because he would lose. So we should not be cowed by his rhetoric or his campaign of sabotage, outrageous as it may be.

“The one weapon that is most needed in our arsenal is confidence. Despite the global instability, Britain is secure at home. Nato is strong. Russia is weak. It is not complacent to point this out.”

Trump could give ground

Mr Trump has insisted he would not make a deal to end the Ukraine war without Mr Zelensky, who has demanded a security guarantee – some kind of commitment that America would be willing to enforce the terms of any peace deal – from the US.

“We should draw reassurance from our place in Nato, recognising we are the very beneficiaries of the same security guarantees President Zelensky so desperately seeks, and then use that assuredness to back Ukraine to the hilt,” said Sir Tony.

But Mr Trump could give ground to Putin and is expected to arrive at the meeting armed with a series of financial incentives hoped at smoothing the path to a peace deal.

Sir Tony cautioned that Russia’s territorial gains should not be overstated, saying “Russia seized less than 0.4 per cent of Ukraine’s territory in the first six months of this year even as the toll of Russian dead and wounded passed one million.”