On Friday, Trump said that at a gala dinner at Blenheim Palace the night before he and May spoke for nearly 90 minutes and had "probably never developed a better relationship".
Only hours after arriving, Trump made the prime minister's life even more hard, with scathing criticism of her in a newspaper interview.
"Just make sure we can trade together, that's all that matters", he said.
He first retold the false story in an interview with The Sun, a British newspaper. "I don't think we see it as rude".
His visit has sparked opposition since May invited the president to a prestigious state visit when she became the first world leader to meet Trump at the White House following his inauguration. It's an accurate representation of his politics which are so immature. But within days, two senior ministers had quit, departures which Trump said earlier in the week had left Britain in turmoil.
"If they do a deal like that, we would be dealing with the European Union instead of dealing with the United Kingdom, so it will probably kill the deal", Trump told The Sun, a conservative British newspaper.
"She wanted to go a different route".
"I actually told Theresa May how to do it but she didn't agree, she didn't listen to me", Trump added. "And that is fine", he said.
The Sun's write-up of its interview, which was recorded, quoted him describing her as a "nice person" and saying they get along "very nicely".
"I think he has done a bad job on crime, if you look, all of the awful things going on there, with all of the crime that is being brought in".
The government published its blueprint on Thursday calling for closer trade ties with the European Union after it leaves the bloc next March.
"If they do that, then their trade deal with the United States will probably not be made".
May about how she should negotiate with the European Union but he didn't say what he'd advised. "The real reason Trump blames my friend @SadiqKhan for the terror attacks previous year is simple", he tweeted.
Speaking to HuffPost UK after the press conference, Tory MP Nigel Evans, who backed Brexit in the referendum, said he was not completely reassured by Trump's remarks.
In the wake of the interview, White House press secretary Sarah Sanders issued a statement that appeared aimed to smooth things over.
It is widely believed that that the president will visit his Turnberry resort in South Ayrshire to relax, and likely play golf, on Saturday.
Putin's government is accused by May's of unleashing a deadly nerve agent in the English city of Salisbury.
Eric is understood to have flown in up to 40 American business leaders with him on "Trump Force One", which landed at Aberdeen Airport yesterday.
The US President's Scottish sojourn is classed as a private trip because there are no official visits, but taxpayers face a £5million bill for policing protests while he is there.