It was billed as a triumph of diplomacy for two of the world's great 'silverbacks' as they sought to bring an end to the fighting in Ukraine.

Yet when President Donald Trump and Russia's Vladimir Putin came nose-to-nose in Alaska last week, what may prove the most telling moment of the historic showdown turned out to be the least obtrusive of all.

And it was the work not of an 800lb political gorilla, but a quietly spoken woman who had other things to do that day.

The moment came away from the cameras when, as the two presidents entered a private room at the US military base, Trump handed Putin a letter written by his wife, Melania, then sitting 4,300 miles away in New York.

'The cameras were fixated on everything the two men did in public,' a source close to Mr Trump told the Daily Mail. 'But the real soft power move came in private, from someone who wasn't there. And that was the First Lady.