LONDON — Britain’s ambassador to the United States resigned Wednesday after being branded a fool and made a diplomatic nobody by President Donald Trump following the leak of the envoy’s unflattering opinions about the U.S. administration.

Storm clouds gathered over the trans-Atlantic relationship as veteran diplomat Kim Darroch said he could no longer do his job in Washington after Trump cut off all contact with the representative of one of America’s closest allies.

The break in relations followed a British newspaper’s publication Sunday of leaked documents that revealed the ambassador’s dim view of Trump’s administration, which Darroch described as dysfunctional, inept and chaotic.

“The current situation is making it impossible for me to carry out my role as I would like,” Darroch said in his resignation letter. He had been due to leave his post at the end of the year.

In the leaked documents, he called the Trump administration’s policy toward Iran “incoherent,” said the president might be indebted to “dodgy Russians” and raised doubts about whether the White House “will ever look competent.”