Boris Johnson's diplomatic visit to Russia turns decidedly undiplomatic

It was the first visit by a British Foreign Secretary to Moscow in five years, and it might be another five years before they're asked back.

The meeting between Boris Johnson and Sergey Lavrov will be remembered for a tense exchange, in which the two men traded barbs over Russia's alleged cyber attacks on the UK.

"The person sitting next to me - Boris Johnson - said recently that he had no evidence that Russia meddled in the referendum over Britain's exit from the European Union," Mr Lavrov said during a joint press conference.

"Not successfully!" Mr Johnson retorted. "Not successfully I think is the word. Not successfully is the word I think you needed to use."

"See, he's afraid that if he doesn't contradict me now his reputation in the media back home will be ruined," Mr Lavrov said.

The comment clearly ruffled Mr Johnson, who then put the question of whose reputation was at stake back on Mr Lavrov.

"Sergey, it's your reputation I'm worried about," he said.

"I think it very important that you should recognise that Russian attempts to interfere in our elections, our referendum, whatever they may have been, they have not been successful - so you can reassure yourself on that point.

"And that's an important consideration, because I think had it been successful, that would be an entirely different matter."

Mr Lavrov said Russia had never been aggressive towards the UK, nor accused it of anything, but, on "quite the contrary, we heard accusations put towards us in quite offensive terms".

Mr Johnson's visit to Moscow on Friday was meant to encourage cooperation and mend diplomatic tensions.