The U.K.’s embattled ambassador to the U.S. has resigned, after leaked internal emails sparked a diplomatic incident between Washington and London.

Sir Kim Darroch, who had been due to step down from his post at the end of this year, came under fire after his scathing assessments of President Donald Trump’s administration were made public by an unknown leaker.

His characterization of the Trump White House as “insecure,” “clumsy” and “inept” incensed the president, who branded the diplomat a “pompous fool” and a “very stupid guy.”

Prime Minister Theresa May stood behind Darroch despite Trump’s attacks, prompting the president to widen his criticism to include the outgoing prime minister. With May set to step aside by the end of this month, the incident had raised questions as to whether the next prime minister will remove Darroch from his post as a peace offering to the White House.

In a statement released on Wednesday morning, Darroch acknowledged the “great deal of speculation surrounding my position and the duration of my remaining term as ambassador.”

Rather than allow the issue to drag on, Darroch said he wanted “to put an end to that speculation” and noted that the “current situation is making it impossible for me to carry out my role as I would like.”

“I believe in the current circumstances the responsible course is to allow the appointment of a new ambassador,” Darroch continued.

“I am grateful to all those in the U.K. and the U.S., who have offered their support during this difficult few days,” he wrote. This has brought home to me the depth of friendship and close ties between our two countries. I have been deeply touched.”

Darroch said he was also grateful for the “professionalism and integrity of the British civil service” which he described as “the envy of the world.” Though leaving under a cloud, Darroch stressed he remains “full of confidence that its values remain in safe hands.”

Though Darroch came under withering criticism from those seeking to ingratiate themselves with Trump, his backers maintained that the fault lay with the leaker, not the diplomat.

May defended Darroch’s comments, though stressed she disagreed with his conclusions. Her spokesperson said it was “the job of ambassadors to provide honest and unvarnished opinions.”

Responding to Darroch’s resignation, the head of the U.K.’s foreign service told the ambassador he was “simply doing your job.” Sir Simon McDonald told Darroch he was “the target of a malicious leak” and that despite the scandal, “You demonstrate the essence of the values of British public service.”

“You are the best of us,” McDonald added.