He was quoted by the Telegraph as saying: "Theresa May has got a lot of great qualities - I am not sure if it is the right leader at the right time".
"We agreed today that as the UK leaves the European Union we will pursue an ambitious US-UK free trade agreement", she said. "It is terrible to hear the inflammatory language that he uses and I am embarrassed that (Prime Minister) Theresa May has done so much to welcome him".
He said it was different to when former U.S. president Barack Obama tried to help the Remain campaign during the 2016 European Union referendum campaign by saying the United Kingdom would be at the "back of the queue" for a trade deal with the USA if left the EU.
"Prime Minister as I just said she's going to make a decision as to what she's going to do", he said.
"Thank you very much for saying that".
But after talks with May at her Chequers country retreat over a lunch of Dover sole, Chiltern lamb and lemon meringue pie, Trump said he thought a post-Brexit trade deal would be possible.
The sovereign is above politics and she does not reveal her personal views.
US President Donald Trump has seemingly breached royal protocol by discussing his private conversation with Queen Elizabeth II who he says thinks Brexit is a "very complex problem", according to an interview with British media.
The blimp, designed by Leo Murray, flew over Parliament Square in London on Friday when organizers said almost 250,000 people took to the streets to mark Trump's first visit to the U.K.as president.
Prime minister faces critical moment as David Davis quits
Born Alexander Boris de Pfeffel Johnson, he is also known for his displays of questionable sportsmanship. Mr Davis's exit may embolden Brexiteer backbench MPs with concerns about Mrs May's leadership.
Build-A-Bear CEO apologizes after 'heartbreaking' sale crowds
The company said they didn't expect the large response to Thursday's deal, which capped the price for a stuffed animal at $29. Shawn Jackson took one of the coupons being handed out at the Build-A-Bear store at La Plaza Mall in McAllen, Texas.
Robinhood Exchange | Adds Support for Litecoin and Bitcoin Cash
Fintech startup Robinhood is expanding its cryptocurrency trading product with two new token listings. Robinhood cofounder Vlad Tenev had criticized existing cryptocurrency exchanges.
The president said he assumed Putin was ruthless, as he prepared to leave for Helsinki in advance of the summit.
Bart Hordijk, market analyst at Monex Europe, said: "The pace at which she (May) is now losing friends is steep, even for her". He obviously likes me, and says very good things about me. Plans to fly it above the Trump Turnberry golf course while the president visits were also denied because of airspace restrictions.
"Whatever you do is OK with me", Trump told the press conference. "The weather is handsome, and this place is incredible!"
Giant balloons depicting Trump as an orange baby were flown at the demonstration.
People held placards reading "Ex-pat for a reason", "No place for Trump's hate", "Trump, racist warmonger, out!", "Dump Trump", "No trade with Trump" and "Trump kidnaps kids".
A mass protest in London on Friday drew more than 250,000 people, organisers claimed.
Brexit Secretary David Davis and Johnson, the former foreign secretary, both quit this week to protest May's trade plan.
Scuffles broke out at one point as attendees - who chanted slogans including "We love you Donald" - passed a nearby anti-fascism protest.