London: Britain’s ambassador to the US has resigned over the publication of confidential diplomatic cables that criticised President Donald Trump’s administration as inept, insecure and incompetent.

A huge cache of cables and briefing notes from Sir Kim Darroch’s embassy were leaked to the Mail on Sunday newspaper and infuriated the President, who immediately announced he would "no longer deal" with Darroch, who was disinvited from a state dinner at the White House on Monday.

Ambassador Kim Darroch, whose leaked assessments of the Trump administration have sparked a row between the allies. Credit:AP

And more damaging comments were anticipated in part two of the Mail story, expected to come out this weekend.

Darroch was backed by the UK government and Prime Minister Theresa May. But the man most likely to be prime minister within the month, Boris Johnson, hinted on Tuesday that he would replace Darroch and emphasised the importance of the US alliance.