Johnson on Thursday backed Trump's tweets about outgoing Prime Minister Theresa May, in which he criticized her handling of Brexit. And he praised the British Embassy for being one of the "very few safe spaces" for Democrats and Republicans to come together.
Johnson's opponent, British foreign minister Jeremy Hunt, said he was outraged that the confidential memos were leaked, leading to Darroch's resignation.
Mr Darroch, who has worked in the diplomatic service for nearly 40 years, said it had become "impossible" to perform his duties and would resign ahead of his planned retirement to end "speculation" over his role.
He was caught red-handed calling President Trump "incompetent insecure and inept" in a series of memos that were leaked to a British newspaper.
Prior to his resignation, a spokesperson for Prime Minister Theresa May's said that Darroch retained the government's "full support". "I'm not going to quote from our reports home, but there may be some similarities".
"And that will be the view also in Washington, I think the ambassador there will be providing very regular updates".
"He has an unbelievably strong commitment to us staying in the European Union and that is worrying", William Cash, a Brexiteer member of Parliament in the Conservative Party, told Sky News. "When it comes to the context of what the president has said about the Brexit deal, I find it hard to disagree".
He believes those with access to Sir Kim's memos would be limited.
Lindsey Graham blamed the press for Kim Darroch's sudden resignation as the United Kingdom ambassador to the U.S. shortly after Donald Trump angrily announced he would no longer work with the foreign official.
Within the leaked cables, Kim Darroch allegedly known as Trump "inept" and "uniquely dysfunctional", in maintaining with a file from the On each day basis Mail published Sunday. "Standing up for Britain means standing up for the finest diplomats on the enviornment". British authorities continue to hunt for the source of the leak.
Sir Alan Duncan told the Commons he had not ruled out a hack - but said there was now no evidence of one. Johnson, however, stressed his good relations with the White House and the importance of the trans-Atlantic relationship. How many will tone down their language in the future for fear of leaks?
British ambassadors are nearly always professional diplomats rather than political appointees.
Gatherings were frequently bipartisan, drawing guests from the Trump and Obama administrations, who mingled with journalists and members of prominent think tanks.
Darroch's grand residence in northwest Washington became a go-to gathering spot for Trump administration officials.
Sir Kim's emails had been leaked to the Daily Mail describing the USA president's administration as "inept".
Scotland's First Minister Nicola Sturgeon, the leader of the separatist Scottish National Party, said Darroch had been "forced out" for doing his job. Johnson wants a sweetheart trade deal with Trump that would open our National Health Service to USA corporate takeover. During his own race in 2016, he referred to himself as "Mr. Brexit," and even suggested that Nigel Farage, a key architect of the Brexit victory, would make a fine ambassador to Washington.
Farage said this week he was not the right man for the job, but on Wednesday, after Darroch's resignation, tweeted: "The right decision, time (to) put in a non-Remainer who wants a trade deal with America".
It's unclear whether May will have time to name a replacement before she leaves office later this month. "I regret what happened and I'm sure he does too".