British ambassador to the United States Kim Darroch announced his resignation Wednesday, saying it was "impossible" to continue in his role following the leak of diplomatic cables featuring comments critical of U.S. President Donald Trump.
"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," Darroch said in a statement.
He had been Britain's top diplomat in Washington since 2016.
Darroch's characterizations of Trump included describing the U.S. leader as "inept," "insecure" and "incompetent" and his administration as "uniquely dysfunctional."
The leaked cables were intended for the eyes of senior British ministers and civil servants, but officials believe the leaker will be found among British politicians or officials, not a foreign government.
Trump responded on Twitter by calling Darroch "a very stupid guy" and a "pompous fool," and had declared he would "no longer deal" with him.