The comments from Mr Trump will send shockwaves through Westminster - and emerged as the prime minister hosted him at a lavish banquet at Blenheim Palace, the birthplace of Sir Winston Churchill.
"I'm certainly going to Turnberry and I'll see him there". And he warned that Britain's trade relationship with the USA could be in jeopardy if May follows through with her "soft" Brexit blueprint. Foreign Secretary Boris Johnson and Brexit Secretary David Davis both quit the government this week in protest.
May's plan "will definitely affect trade with the United States, unfortunately in a negative way". "Whatever you're gonna do is OK with us, just make sure we can trade with you, that's all that matters".
However, while Trump and May exchanged warm words, tens of thousands of protesters marched against the US president through central London, bringing much of the British capital to a standstill. He was decidedly critical of May and her Brexit plan, saying he "would have done it much differently". "She wanted to go a different route", Trump said, adding that May "didn't listen".
Trump said May had ignored his advice on how to negotiate Britain's exit from the European Union. And since bullies only respond to strength, from now onward I should be prepared to be much stronger.
British Prime Minister Theresa May sits with Foreign Secretary Boris Johnson as she holds the first Cabinet meeting of her new team inside 10 Downing Street, in London, on June 12, 2017.
"He thought she was great on North Atlantic Treaty Organisation today and is a really terrific person", Sanders said.
Trump claimed he did not criticize Prime Minister Theresa May, even though the "Sun" released audio clips showing that he did.
"I said tremendous things, and fortunately we tend to record stories now so we have it for your enjoyment if you'd like it", Trump said.
She said: "I heard the turn of phrase that the President used earlier, but let me be very clear about this: we will be leaving the European Union, and we are leaving on the 29th of March, 2019".
Mr Coveney said "contradictions" remain within the UK's position and the EU's red-lines.
Amidst the angry anti-Trump protests in London, outraged Brits flew a massive Donald Trump baby blimp with mini hands through the sky! That is fake news. "It didn't put in what I said about the prime minister, and I said tremendous things". I haven't been there in a long time. "I think they like me a lot in the UK".
On Thursday night, several protesters gathered outside Winfield House, where Trump is staying, banging pots and blowing vuvuzelas in the hopes of keeping him awake.
In a wide-ranging interview he also blamed the mayor of London for high crime rates in the city and failing to tackle terrorism.
"I think it changed the fabric of Europe and, unless you act very quickly, it's never going to be what it was and I don't mean that in a positive way".
Speaking to the Sun, Mr Trump attacked Mr Khan over the wave of terrorist attacks in London a year ago and accused him of doing "a awful job".
"We may be a small country, but we're a great one too", he continues. Instead, he said, May went "the opposite way", and the results have been "very unfortunate".