"I said (to Theresa May), "Make sure you have a carve out, you have to have a carve out" where no matter what happens they have the right to make a deal with the United States", Trump said in the interview.
The warning comes after key cabinet members David Davis, the Brexit secretary, and foreign secretary Boris Johnson quit over the proposed deal she presented during an away day at her country house, Chequers, last Friday.
"He told me I should sue the EU", May told BBC interviewer Andrew Marr on Sunday.
The president's clarification confirms that he was not looking to insult the prime minister personally, but only to criticize a plan that will have a huge impact on worldwide politics. And he marveled during the joint appearance at Chequers, the 16th century country residence used by British prime ministers since the 1920s.
"Not go into negotiation, sue them".
"It's a very odd thing to do, to come on a visit to another country, to meet that country's prime minister, and then announce that you would like to see as her successor a person who's just resigned from her government", he said.
"It puts an end to the vast membership subscriptions we pay to Brussels, delivering a Brexit dividend to support domestic priorities like our long-term plan for the NHS".
"We agreed today that as the United Kingdom leaves the European Union we will pursue an ambitious USA -U.K. trade deal", May said Friday at a news conference with Trump at Chequers, her country estate.
But Trump's visit came against the backdrop of tensions in the trans-Atlantic alliance: Mass protests of Trump in the streets of London, his second-guessing of May's handling of Brexit in an interview with a British newspaper and a string of global summits that have often pitted the US against its traditional allies.
Scottish Protesters Hurl Abuse As Trump Golfs
And Greenpeace flew a paraglider with a banner message saying "Trump Well Below Par" above the Turnberry resort on Friday evening. The six metre tall balloon has become a symbol of the protests against the US President's first official visit to Britain.
Fit-again Croatia ready for seismic event, says coach Dalic
Chelsea captain Gary Cahill could well be the next player to fall foul of Southgate's focus on developing a team for the future. In the first game, he talked us up to give us self-belief and told us we were still good players despite this crisis.
Thai boys rescued from cave mourn hero diver
As tears of joy and relief flowed, Dr Harris was told his father had died shortly after the mission was complete. The Thai Navy SEALs issued a statement on July 11 thanking the South Australian for his incredible efforts.
Some lawmakers in her deeply divided Conservative Party have cast May's "business-friendly" Brexit plan as a betrayal that would leave Britain too close to the European Union and warned that she might face a leadership challenge.
He said the Prime Minister had acted in an "untrusting way" by flouting her previous red lines on leaving the EU.
Mr Khan added: "We have a special relationship with the U.S., it's like having a best friend".
On Friday he repeated his opinion that Johnson "would be a great prime minister" - but added that May was doing "a fantastic job", too.
He said: "I can not find someone who supported Leave within the Conservative MPs who's happy with the proposals if you talk to them in private".
"I would have done it much differently", Trump said. Over two lakh people came out on the streets of London to oppose the American president's four-day trip to Britain, said Stop Trump, the group which organised the protest, Al Jazeera reported.
President Donald Trump and Queen Elizabeth II inspecting a Guard of Honour.
"We have this stupidity going on, pure stupidity, but it makes it very hard to do something with Russia because, anything you do, it's like: "Russia, oh he loves Russia", Trump said at the press conference before news of the indictment.