Former U.S. Ambassador to the United Nations John Negroponte said on Monday that President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE roared into the U.K. during a trip last week, but left like a “lamb.”

"He went in like a lion, came out like a lamb," Negroponte told Hill TV's Krystal Ball on "Rising," when asked about Trump's criticism of Prime Minister Theresa May and praise for former Foreign Secretary Boris Johnson during the visit.

"I didn't see the very end of the visit with the queen, but by then he was on very good behavior," he added.

Negroponte's interview comes after Trump's first visit to the U.K. since taking office in 2017, which was met with massive protests in London and Scotland.

The president made headlines during the trip last week after he gave an interview with The Sun, in which he lambasted May's Brexit proposals and said she ignored his advice on negotiations.

Trump also praised May's potential political rival Johnson, who resigned last week as foreign minister, saying he would make a "great prime minister."

However, Negroponte said he doubted that Trump's comments to the publication would have a negative impact on the prime minister.

"Britain has an old democracy. They know how to defend themselves. They have a strong parliamentary system. I actually have some doubt as to whether the remarks he made will hurt Mrs. May politically. That may have been a thought of his by saying what he said and praising Boris Johnson but it's just as feasible that the British will get their bats up and say 'Who's this person from the outside to criticize our leaders?' So I think it's a double-edge sword," he said.

— Julia Manchester