Donald Trump says Conservative leadership hopeful Boris Johnson is a "very good guy" and would be an "excellent" prime minister.
The US president claims he has studied the contest to succeed Theresa May "very hard" and has been asked for endorsements by some of the candidates, but noted that the former foreign secretary - who he could meet during his state visit to the UK next week - is "very talented".
He told The Sun: "I actually have studied it very hard. I know the different players. But I think Boris would do a very good job. I think he would be excellent. I like him. I have always liked him."
Mr Trump has previously described Mr Johnson as "a friend of mine" and suggested to reporters last week that he could set up a meeting with him and Brexit Party leader Nigel Farage when he arrives in the UK.
The Republican will be welcomed by outgoing prime minister Mrs May at the start of his three-day state visit on Monday, and suggested he could officially endorse one of the 12 candidates to replace her.
"I don't want to say who, but other people have asked me for endorsements, yes," he told The Sun.
"I could help anybody if I endorse them."
He added that he would look favourably on Jeremy Hunt, but said he was not such a fan of Michael Gove.
The environment secretary accused Mr Trump of "sabre rattling" over his stance on Iran, and Mr Trump claimed the UK should be more welcoming of his aggressive approach to the Middle Eastern country.
He also criticised the approach taken by the government to Brexit negotiations, which he said had left the EU with "all the cards" and "all the advantage".
"I think that the UK allowed the European Union to have all the cards - and it is very hard to play well when one side has all the advantage," he said.
"They had nothing to lose. They didn't give the European Union anything to lose."
US national security adviser John Bolton told Sky News earlier this week that Mr Trump was a supporter of Brexit and was looking forward to working with a "fully independent Britain".
Mr Bolton said the president hoped to do a trade deal with the UK soon after it leaves the EU, which is currently scheduled for 31 October.
Mr Trump said he was a fan of Foreign Secretary Jeremy Hunt
The US president could well offer further commentary on British politics during his state visit next week, which will see him meet with the Queen and other senior members of the Royal Family.
He will not be meeting new mother the Duchess of Sussex - not that Mr Trump would have been anticipating a welcome reception.
Asked about Meghan's backing of rival Hillary Clinton in the 2016 presidential election, and suggesting she would leave the US if Mr Trump won, he told The Sun: "I didn't know that. What can I say? I didn't know that she was nasty."
But he added that it was "nice" to have an American in the Royal Family.