Scotland's First Minister Nicola Sturgeon has said foreign secretary Boris Johnson is "not fit for high office".

At the start of the SNP's spring conference, she responded to comments by the foreign secretary criticising Britain's Brexit strategy.

Ms Sturgeon said: "I think it's further evidence that Boris Johnson's not fit to hold the high office that he does.

"It's not the first time he's made embarrassing, ill-judged comments... but it also shows, in my view, that Boris Johnson's not really interested in the best interests of the country, he's not interested in people's jobs and livelihoods.

"He's just interested in currying favour with the hardline Brexiteers in his own party."

Boris Johnson criticised the UK government's Brexit talks strategy, saying it lacks "guts" and suggested Donald Trump could do a better job.

The foreign secretary also took a swipe at Chancellor Philip Hammond, calling the Treasury "the heart of Remain", in comments to a private dinner.

He said the Brexit talks were heading for "meltdown" and Leave supporters may not get the deal they expected.

Brexit-supporting Tory MPs applauded the foreign secretary but Mr Hammond said his "advice to colleagues" was to engage with the EU and to understand their concerns.

In the recording, obtained by Buzzfeed, Mr Johnson warns the UK could remain "locked in orbit around the EU" and claimed the Irish border issue - one of the main sticking points in talks with Brussels - had been allowed to dictate "the whole of our agenda".

"It's so small and there are so few firms that actually use that border regularly, it's just beyond belief that we're allowing the tail to wag the dog in this way," he said.

Downing Street said Theresa May had "full confidence" in Mr Johnson.