NICOLA Sturgeon has hit back at the US president after his bizarre Twitter rant.

Donald Trump, in a fresh outburst aimed at Kim Darroch, branded the UK ambassador to the US “a very stupid guy” and vowed never to deal with him again.

The outburst follows on from a similar rant last night which was prompted by a leaked document in which Darroch called the US president “inept”.

Downing Street has said Theresa May has full faith in the ambassador.

Trump’s rant also took aim at the Prime Minister, saying she had made a “mess” of Brexit and that she should have followed his advice on the matter.

READ MORE: Donald Trump hits out at 'very stupid' UK official in Twitter rant

The First Minister has since hit back at Trump while challenging the next prime minister to confront this kind of behaviour once they take office.

She tweeted: “Extraordinary stuff. And huge litmus test for next PM – will he stand up for the ability of diplomats to do their jobs or give in to this kind of behaviour by the US President?”