The president's latest criticism, which came in a series of tweets, followed the president's declaration on Monday that the U.S. "will no longer deal with" Darroch after diplomatic cables leaked to the Mail in which Darroch called Trump's administration "inept" and "incompetent."
In a sign of just how far tensions have increased, U.K. Foreign Secretary Jeremy Hunt tweeted back at Trump that his comments were "disrespectful."
Darroch's future relationship with the U.S. was unclear. He was also 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 the leak.
At the same time, May's government has made it clear it's backing him.
"We have made clear to the U.S. 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. Sir Kim Darroch continues to have the Prime Minister’s full support," a May spokesman said in a statement.
Despite President Trump's tweet that "we will no longer deal with" Darroch, the State Department said Tuesday it will and has not been given any instructions not to.
"We will continue to deal with all accredited individuals until we get any further guidance from the White House or the president, which we will of course abide by the president's direction," said spokesperson Morgan Ortagus.
ABC News' Conor Finnegan contributed to this report.