Kim Darroch has resigned as British ambassador to the United States, following soured relations with the US President's administration.

It comes after leaked diplomatic documents described Donald Trump and his administration as "inept" and "uniquely dysfunctional", according to the memos published by the Mail on Sunday.

Mr Darroch reportedly said Mr Trump's presidency could "crash and burn" and "end in disgrace", in the cache of secret cables and briefing notes sent back to Britain seen by the newspaper.

In a letter to Simon McDonald, the permanent under secretary at the Foreign and Commonwealth Office, Mr Darroch said he was ending speculation about his position in light of the leaking of confidential documents related to his time as ambassador.

The leak of the diplomatic dispatches has soured relations with Mr Trump's administration and prompted a Twitter tirade from the US president, who described Mr Darroch as a "pompous fool" and a "very stupid guy" who had been foisted on the US. 

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In his resignation letter, Mr Darroch wrote: "Since the leak of official documents from this Embassy there has been a great deal of speculation surrounding my position and the duration of my remaining term as ambassador. I want to put an end to that speculation.

"The current situation is making it impossible for me to carry out my role as I would like.

"Although my posting is not due to end until the end of this year, I believe in the current circumstances the responsible course is to allow the appointment of a new ambassador.

"I am grateful to all those in the UK and the US, who have offered their support during this difficult few days. This has brought home to me the depth of friendship and close ties between our two countries. I have been deeply touched.

"I am also grateful to all those with whom I have worked over the last four decades, particularly my team here in the US. The professionalism and integrity of the British civil service is the envy of the world. I will leave it full of confidence that its values remain in safe hands."

British Prime Minister Theresa May said that she had spoken to Mr Darroch and "told him that it is a matter of great regret that he has felt it necessary to leave his position as ambassador in Washington".

Speaking in the House of Commons Mrs May said: "The whole cabinet rightly gave its full support to Sir Kim on Tuesday. Sir Kim has given a lifetime of service to the United Kingdom and we owe him an enormous debt of gratitude.

"Good government depends on public servants being able to give full and frank advice. I want all our public servants to have the confidence to be able to do that and I hope the house will reflect on the importance of defending our values and principles, particularly when they are under pressure."

Downing Street had backed Mr Darroch after Mr Trump warned on Monday the White House would have nothing more to do with him.

The first indication of the rift became evident when the ambassador was "uninvited" to a White House dinner on Monday evening, held in honour of the Emir of Qatar.

Mr Darroch was also not attending a meeting between Ivanka Trump, an advisor to President Trump, and UK International Trade Secretary Liam Fox in Washington.

In a further sign of complications in the special relationship, an expected meeting between Dr Fox and US commerce secretary Wilbur Ross failed to take place - officially due to "diary clashes".

A formal civil service leak inquiry has been launched into how Mr Darroch's messages were disclosed to the Mail on Sunday, but MPs called for the police to investigate.

In a post on Twitter, the Irish Ambassador to the United States, Daniel Mulhall, paid tribute to Mr Darroch.