US President Donald Trump has said Boris Johnson would do "a great job" as UK prime minister and they would have "a very good relationship".
"He's a different kind of a guy but they say I'm a different kind of a guy too," Mr Trump told reporters.
Outgoing prime minister Theresa May "has done a very bad job with Brexit", he added.
Mr Johnson is the frontrunner in the contest to become the next Tory leader and UK prime minister.
He and Foreign Secretary Jeremy Hunt are the final two candidates, with the winner announced on 23 July and taking office the next day.
President Trump said he had spoken to Mr Johnson on Thursday, adding: "We get along well."
"I like Boris Johnson, I always have," he told reporters in the Oval Office in Washington DC.
Commenting on the UK's Brexit negotiations, he said: "It's a disaster and it shouldn't be that way."
"I think Boris will straighten it out," he added.
The US president has previously said Mr Johnson would be an "excellent" choice as Conservative leader.
He has also been critical of Mrs May's Brexit policy in the past, saying he was surprised by how "badly" the negotiations had gone.
Some 160,000 Conservative Party members are voting in a postal ballot to elect the next leader. Ballots must be returned by 17:00 BST on Monday.