Boris Johnson urged Donald Trump to back Ukraine in a one-on-one meeting on the sidelines of the Republican National Convention.

It comes after Mr Trump picked as his running mate JD Vance, an Ohio senator and vocal critic of support for Ukraine.

The former prime minister, who enjoys warm relations with his former counterpart, shared an image of himself posing with Trump on Tuesday.

Mr Johnson said: “Great to meet president Trump who is on top form after the shameful attempt on his life.

“We discussed Ukraine and I have no doubt that he will be strong and decisive in supporting that country and defending democracy.”

Mr Johnson has been a fierce advocate for supporting Kyiv and has repeatedly called on the West to bolster its supply of weapons to the country since the Russian invasion in 2022.

He has made the case that America’s investment in Ukraine’s defences represents value for money, compared with the cost of countering an emboldened Moscow.

In particular, he has argued that Trump, whom he has endorsed in November’s US election, would not want to begin a second term by presiding over Russia’s victory in Ukraine.

“If you are the party of Ronald Reagan, if you want to make America great again, then you don’t begin a new Republican presidency… by conceding victory to Vladimir Putin,” he said earlier this year.

However, those arguments face an increasingly difficult audience among Trump and his Republican allies in Congress, who have argued Europe should be shouldering the burden of the cost.

Mr Vance, who has been a fierce opponent of US funding for Kyiv – is likely to only harden that stance.

Mr Johnson’s meeting with Trump comes just days after the former president, 78, survived an assassination attempt at a rally in Pennsylvania.

The Republican presidential nominee can be seen sporting a bandage over his right ear, which was grazed by a bullet, in the photo Mr Johnson shared on his social media.