President Donald Trump says he has a very strong relationship with British Prime Minister Theresa May, having earlier scorned her Brexit strategy which he said had probably killed off hope for a future US-British trade deal.
In an interview published hours before he was due to lunch with May and take tea with Queen Elizabeth on Friday, Trump chided the "very unfortunate" results of the prime minister's strategy for negotiating Britain's departure from the European Union.
"If they do a deal like that, we would be dealing with the European Union instead of dealing with the UK, so it will probably kill the deal," Trump said.
"I would have done it much differently," he told told the Rupert Murdoch-owned Sun, which urged readers to back Brexit before a referendum in June 2016.
"I actually told Theresa May how to do it but she didn't listen to me."
Trump also heaped praise on Boris Johnson, who resigned as foreign secretary this week along with Brexit Secretary David Davis in protest at May's strategy.
Johnson, the president said, "would be a great prime minister".
No sitting US president has ever made such biting public criticism of a British prime minister while visiting and his comments undermined May in her party, her country and abroad.
But as the leaders met for talks at May's official country residence Chequers both tried to play down the matter.
"We really have a very good relationship," Trump said. "Today we are talking trade and we are talking military."
Asked if he regretted his comments to the Sun, Trump looked away and shook his head.
"We've got a lot to discuss," May said, adding they would talk about the British-US "special relationship" and trade opportunities.
Sterling fell half a per cent to a 1 1/2-week low of $1.3131, partly on Trump's comments.
"Where are your manners, Mr President?" asked junior minister Sam Gyimah.
As Britain prepares to leave the EU on March 29, 2019, supporters of Brexit have made much of the so-called special relationship with the United States.
Many have cast May's plan as a betrayal, including MPs in her deeply divided Conservative Party, who have warned she might face a leadership challenge.
For supporters, Trump and Brexit offer the prospect of breaking free from what they see as obsolete institutions and rules.
But for many British diplomats, Brexit marks the collapse of a 70-year strategy of trying to balance European integration with a US alliance based on blood, trade and intelligence sharing.
Trump has frequently angered British politicians. Late last year, May criticised him for retweeting a message by a member of a British far-right group and the Speaker of parliament has said Trump would not be welcome to address the chamber.
More than 64,000 people have signed up to demonstrate in London against Trump's visit.
On Friday, protesters flew a blimp depicting him as an orange, snarling baby outside the British parliament.