By Andy Hayes, news reporter
Theresa May has given the UK's ambassador to the US her "full support" after Donald Trump said he would no longer deal with Sir Kim Darroch.
In a couple of tweets, the US president also said Mrs May had made a "mess" of Brexit, and that the "good news" for the UK was that "they will soon have a new prime minister".
Mr Trump's attack follows the leaking of memos from Sir Kim, in which Mr Trump is described as "incompetent", "inept" and "insecure".
In his messages, the US president is scathing about Sir Kim, claiming he is "not liked or well thought of within the US", adding: "We will no longer deal with him."
He said previously that Sir Kim "has not served the UK well".
Downing Street responded by saying Sir Kim "continues to have the prime minister's full support".
A spokesperson added: "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.
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"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."
Mr Trump's comments – just a month after his state visit to the UK – came ahead of a meeting between International Trade Secretary Liam Fox and his daughter Ivanka in Washington later on Monday.
Alexander Vershbow, a former US ambassador to Russia and South Korea, told Sky News it was not surprising that the president had tweeted such comments.
"President Trump is very thin-skinned when it comes to public criticism," he said.
Mr Vershbow added that Sir Kim would probably "have to shorten his tenure in Washington", but he doubted the relationship between the US and UK would be damaged.
Also on Twitter, Mr Trump said he had "told" Theresa May how Brexit "should be done", but she "decided to go another way", adding: "What a mess she and her representatives have created."
The only person Mr Trump had something good to say about was the Queen, who he was "impressed with" during the state visit.
I have been very critical about the way the U.K. and Prime Minister Theresa May handled Brexit. What a mess she and her representatives have created. I told her how it should be done, but she decided to go another way. I do not know the Ambassador, but he is not liked or well….
— Donald J. Trump (@realDonaldTrump) July 8, 2019
….thought of within the U.S. We will no longer deal with him. The good news for the wonderful United Kingdom is that they will soon have a new Prime Minister. While I thoroughly enjoyed the magnificent State Visit last month, it was the Queen who I was most impressed with!
— Donald J. Trump (@realDonaldTrump) Read More – Source[contf] [contfnew]