Donald Trump says he will no longer work with the British ambassador whose leaked memos described the US president as “inept” and “dysfunctional”.

Britain has expressed regret about the leaking of confidential memos from Kim Darroch, UK ambassador to Washington, but not for the content.

Dating back to 2017, they offered frank assessments of Mr Darroch’s view of the White House, stating: “We don’t really believe this Administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept”.

After an initially restrained response, Mr Trump has fired back on Twitter saying he “will no longer deal” with the British ambassador.

“I do not know the Ambassador, but he is not liked or well thought of within the U.S. We will no longer deal with him,” Mr Trump tweeted.

His Twitter post also criticised outgoing British Prime Minister Theresa May about Brexit.

“What a mess she and her representatives have created. I told her how it should be done, but she decided to go another way,” he said.

“The good news for the wonderful United Kingdom is that they will soon have a new Prime Minister. While I thoroughly enjoyed the magnificent State Visit last month, it was the Queen who I was most impressed with!” he wrote.

….thought of within the U.S. We will no longer deal with him. The good news for the wonderful United Kingdom is that they will soon have a new Prime Minister. While I thoroughly enjoyed the magnificent State Visit last month, it was the Queen who I was most impressed with!

— Donald J. Trump (@realDonaldTrump) July 8, 2019

A spokesperson for Ms May said the incident was a matter of regret while the UK Trade minister Liam Fox said he would apologise to Mr Trump’s daughter Ivanka at their meeting.

The two leaders described the leak as “unacceptable” and not in keeping with the behaviour expected of the British public service.

However senior politicians have defended the ambassador whose revelatory memos are at the centre of the developing scandal.

Foreign minister Jeremy Hunt, who is vying to be the next British prime minister, promised “serious consequences” for whoever who had leaked the memos but did not condemn the content.

“I have made it clear that I don’t share the ambassador’s assessment of either the US administration or relations with the US administration, but I do defend his right to make that frank assessment,” said Mr Hunt.

“What we will not allow to happen is any interruption in the superb relationship that we have the United States, which is our closest ally around the world.”

“I hope we get to the bottom of it and of course there will be very serious consequences if and when we find out who’s responsible.”@Jeremy_Hunt addresses the UK ambassador’s controversial Trump comments leak. pic.twitter.com/hRJLkHsGWU

— RT UK (@RTUKnews) July 8, 2019

The revelations come at a time when Britain is hoping to strike a major trade deal with its closest ally after it leaves the European Union, an exit currently scheduled for October 31.

Mr Fox, who is visiting Washington, said he would apologise to Mr Trump’s daughter Ivanka, whom he was due to meet.

“I will be apologising for the fact that either our civil service or elements of our political class have not lived up to the expectations that either we have or the United States has about their behaviour, which in this particular case has lapsed in a most extraordinary and unacceptable way,” he said.

“Malicious leaks of this nature … can actually lead to a damage to that relationship, which can therefore affect our wider security interest.”

Nigel Farage, leader of the Brexit Party and long a thorn in the side of British governments, said figures such as Mr Darroch would be “not be around” if ex-foreign minister Boris Johnson, the other candidate seeking to replace Ms May, was chosen by Conservative Party members.

An inquiry is now being held to determine who was behind the disclosure. Ms May’s spokesman said if there was evidence of criminality, then the police would be involved.

-with AAP