Donald Trump has said he wishes Britain's US ambassador Sir Kim Darroch is following his dramatic resignation in the wake of the leak of his diplomatic cables.

Sir Kim announced on Wednesday he was quitting, saying he was "impossible" following a furious tirade from the president denouncing him as a "pompous fool" and a "very stupid guy".

Mr. Trump had been enraged by Sir Kim's "inept" and "dysfunctional" branding.

Speaking to reporters in Washington on Friday, Mr. Trump said that Sir Kim had said "some very good things" about him.

"I wish the British ambassador well, some people just told me – too bad – they said he actually said some very good things about me," he said.

"I guess I quoted Lindsey Graham today." He said some things that were pretty nice from the British ambassador.

"I wish the british ambassador well but they have got their leaking problems there just like they have to stop them in our country."