DONALD Trump has congratulated Boris Johnson on becoming the new Tory leader and Prime Minister.

The US President wrote on Twitter: “Congratulations to Boris Johnson on becoming the new Prime Minister of the United Kingdom. He will be great!”

READ MORE: Boris Johnson named as new Prime Minister 

Mr Trump has repeatedly praised the former foreign secretary in recent months, insisting he would do a “great job” in Downing Street and that the pair would have a “very good relationship".

Earlier this month, he told reporters in Washington DC: "He's a different kind of a guy but they say I'm a different kind of a guy too.”

He added: "I like Boris Johnson; I always have.”

And in an interview with The Sun last month, he said Mr Johnson would be an “excellent” choice to take charge.

He said: "I actually have studied it very hard. I know the different players. But I think Boris would do a very good job. I think he would be excellent. I like him. I have always liked him.

"I don't know that he is going to be chosen but I think he is a very good guy, a very talented person."

READ MORE: Nicola Sturgeon voices "profound concerns" over PM Boris Johnson 

Tensions have emerged between the UK and US in recent weeks following the publication of leaked cables written by Sir Kim Darroch, the British ambassador to the US. 

Sir Kim – who stepped down following the row – branded Mr Trump’s administration “inept” in diplomatic memos subsequently handed to the Mail on Sunday.

The US President later attacked the diplomat on Twitter, while also accusing Theresa May of foolishness over her failed Brexit plan.

Mr Johnson will be hoping to rebuild the UK's relationship with one of its most important allies, amid hopes of a post-Brexit trade deal with the US.

However, his relationship with Mr Trump hasn’t always been so positive.

In 2015, while mayor of London, he accused the future US President of “quite stupefying ignorance” over remarks he made about supposed no-go areas in London – and insisted he was "unfit to hold the office of president of the United States".