ELLESBOROUGH, England -- President Donald Trump pulled off a diplomatic backflip Friday, reversing himself on trade, Brexit and his critical assessment of British Prime Minister Theresa May while insisting the U.S.-U.K. relationship is "the highest level of special." Just days after lobbing thunderous broadsides at his British hosts, Trump was on his best behavior as he capped his tumultuous two-day visit to the U.K. by dropping by Windsor Castle for tea with the queen.

Trump's pomp-filled visit to the United Kingdom has been overshadowed by massive protests and an interview in The Sun in which he blasted May, blamed London's mayor for terror attacks against the city and argued Europe was "losing its culture" because of immigration.

The president who prides himself on not saying he's sorry did his own version of backtracking at a news conference with May by finding a way to blame his favorite foil for any perceived friction with May, whom he lavished with praise on the heels of questioning her leadership.

"I didn't criticize the prime minister. I have a lot of respect for the prime minister," said Trump. He blamed the newspaper for skipping over his praise of May in a piece published Thursday just as the prime minster played host to Trump at an opulent welcome dinner at a country palace.

The president then urged reporters to listen to a full recording of the interview, which he said would give the full picture. But the audio was already posted on The Sun's website and undermined Trump's contention it would back him up.

The interview was the latest breach of diplomatic protocol by Trump, whose predecessors tended to avoid criticizing their foreign hosts. And it comes at a perilous time for May, whose government is teetering amid contentious negotiations on how the U.K. will leave the European Union.

"Well, I think the deal that she is striking is not what the people voted on," Trump said in the interview. He also praised one of May's political rivals, former foreign secretary Boris Johnson. He backpedaled away the comments Friday, saying of May's Brexit talks: "Whatever you're going to do is OK with us. Just make sure we can trade together. That's all that matters."

May, for her part, praised the strength of the U.S.-U.K. bond. But in a gentle rebuke, said: "It is all of our responsibility to ensure that trans-Atlantic unity endures."

As for her relationship with Trump, she said: "We are friends."

Trump was greeted by massive protests across Britain, including tens of thousands of demonstrators who filled the streets of London alongside a giant balloon over Parliament on Friday depicting him as a cell-phone-toting angry baby in a diaper.

In a frenetic news conference at Chequers, May's official country house, an unrestrained Trump blamed his predecessor for Russian aggression in Crimea, placed fair trade at the center of Britain's efforts to leave the European Union, defended his beliefs immigration has damaged Europe and repeatedly jousted with television correspondents' whose coverage he found critical.

The news conference was a scene in itself, featuring the moos of cows in the distance at the end. Trump at times drew laughs from some British reporters, who jeered his criticism of the media and openly laughed at his numerous boasts.

Interviewed before he left Brussels for the U.K, Trump accused May of ruining what her country stands to gain from its Brexit vote to leave the European Union. He said her former foreign secretary, Boris Johnson, would make an "excellent" prime minister, speaking just days after Johnson resigned his position in protest over May's Brexit plans.

Trump added May's "soft" blueprint for the U.K.'s future dealings with the EU would probably "kill" any future trade deals with the United States.

"If they do a deal like that, we would be dealing with the European Union instead of dealing with the U.K., so it will probably kill the deal," Trump told the paper.

Trump, who has linked his own election to the June 2016 referendum in which a slim majority of British voters supported leaving the EU, complained, "The deal she is striking is a much different deal than the one the people voted on."

He also told the tabloid he'd shared advice with May during Britain's negotiations with the EU and she ignored it.

Tens of thousands of people gathered in London for a series of demonstrations against the president's visit. Marchers gathered near BBC headquarters in central London before walking through the center of the city to Parliament.

Many protesters used humor to convey their opposition. One sign read "Trump wears poorly tailored suits," while another proclaimed: "Overcomb Brexit." One man was selling rolls of "Trump toilet paper" emblazoned with a picture of the president. More protests were planned in Windsor, where the Trumps met the queen later, and in Scotland, where the president is spending the weekend at one of his golf courses.

"I guess when they put out blimps to make me feel unwelcome, no reason for me to go to London," he told The Sun, which is owned by his media ally, Rupert Murdoch, owner of Fox News in the United States.

Trump has been traveling by helicopter to avoid the protests in central London. Police worked overtime, their days off canceled.

Trump acknowledged feeling unwelcome in the city, and blamed it in part on Mayor Sadiq Khan, who gave protesters permission to fly the baby Trump balloon. Trump also blamed recent terrorist attacks there on Khan, who is Muslim. The president claimed Europe is "losing its culture" because of immigration from the Middle East and Africa.

"Allowing the immigration to take place in Europe is a sham," he said. "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."

Khan, whose grandparents hailed from Pakistan, responded by questioning why Trump repeatedly chose him to criticize.

"Paris, Nice, Brussels, Berlin. Cities in America all suffered terror attacks," Khan told British broadcaster Sky News. "And it's for President Trump to explain why he singled me as the mayor of London out and not the mayors of other cities and leaders of other cities."