NBC News has not seen or verified the existence of the diplomatic cables.
LONDON — The U.K.'s top diplomat in the U.S. reportedly views President Donald Trump as "inept," "insecure" and "incompetent," according to leaked diplomatic cables.
Kim Darroch, Britain's ambassador to Washington, D.C., made the highly critical comments about the president and his administration in a series of memos to London, according to the Mail on Sunday newspaper.
NBC News has not seen or verified the existence of the cables.
If true, the leaks provide a rare insight into how a key U.S. ally views the Trump administration behind closed doors.
The memos were reportedly critical of Trump's economic policies, claiming they could wreck the world trade system, described conflicts within the White House as "knife fights" and warned "the worst cannot be ruled out" in regard to allegations of Trump's collusion with Russia.
"We don't really believe this administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept," Darroch wrote in one of a series of leaked documents covering the period from 2017 to the present.
NBC News has reached out to the White House and U.K. ambassador's office for comment.
The U.K. foreign office defended Darroch in a statement, saying that ambassadors are allowed to be candid about their views.
"The British public would expect our Ambassadors to provide Ministers with an honest, unvarnished assessment of the politics in their country," the statement said, adding an ambassador's perspective is not representative of the views of the government.
The statement did not deny the veracity of the leak, instead condemning the apparent breach of protocol.
"It's important that our Ambassadors can offer their advice and for it remain confidential," the statement said.
"Our team in Washington have strong relations with the White House and no doubt that these will withstand such mischievous behaviour."