Trump says US 'will no longer deal with' UK ambassador who called him 'inept' in leaked cables Theresa May's government supported the ambassador, Kim Darroch.

President Donald Trump in a tweet on Monday said that the United States "will no longer deal with" U.K. Ambassador to the U.S. Kim Darroch after his blunt criticism of the president and administration in diplomatic cables was leaked.

In the trove of leaked memos published on Saturday in the Daily Mail, Darroch called Trump "inept" and "incompetent" and described the White House as wildly dysfunctional.

Darroch was disinvited from a dinner Monday night with the president at the Treasury Department in honor of the amir of Qatar, according to a U.S. official. White House officials said this is an example of the kind of treatment Darroch will likely receive in the aftermath of this leak.

On Sunday, Trump said Darroch "has not served the U.K. well, I can tell you that."

"We are not big fans of that man," he added.

In tweets on Monday afternoon, Trump also slammed the U.K. and outgoing Prime Minister Theresa May's handling of Brexit and claimed that he offered May advice that was never taken. The leak raised questions about whether the cables were released in order to embarrass Darroch by Brexit supporters from within the British government. Trump has been in favor of Brexit, and while in London last month met with Brexit leader and friend Nigel Farage at the U.S. ambassador's residence.

"The good news for the wonderful United Kingdom is that they will soon have a new Prime Minister," Trump tweeted after slamming May.

"While I thoroughly enjoyed the magnificent State Visit last month, it was the Queen who I was most impressed with!"

May's spokesperson did not criticize the diplomat and said he continues "to have the Prime Minister's full support."

"We have made clear to the US how unfortunate this leak is. The selective extracts leaked do not reflect the closeness of, and the esteem in which we hold, the relationship. At the same time we have also underlined the importance of Ambassadors being able to provide honest, unvarnished assessments of the politics in their country," a spokesperson said in a statement. "Sir Kim Darroch continues to have the Prime Minister's full support. The UK has a special and enduring relationship with the US based on our long history and commitment to shared values and that will continue to be the case."

The White House did not respond for a request for comment.

ABC News' Kirit Radia contributed to this report.