"I am not pitting one against the other", Trump said.
"The Star-Spangled Banner" was then played and the queen guided the president on a review of the honour guard in the castle courtyard. But the Trumps kept the Queen waiting on the dais in the Quadrangle during the ceremonial welcome. First Lady Melania Trump also reportedly broke another Royal rule herself after failing to curtsy when greeting Queen Elizabeth II. This is his first visit to Harry Potter's homeland since taking office.
On Thursday, the protesters gathered by a large metal fence sealing off the USA ambassador's residence in Regent's Park, where the president will spend his only night in London.
Senate approves symbolic resolution for bigger role in tariff decisions
It is created to give Congress more say about trade penalties imposed by the president in the name of national security. Corker concluded that the vote indicates "strong support" for giving Congress a larger role on tariffs.
Trump said that May may have killed off a trade between the USA and the United Kingdom as a result of her handling of Brexit - hours after her government published its plans in a white paper.
Ms May and Mr Trump both spoke of the importance of the "special relationship" between their two countries, something that Brexit supporters hope will reap benefits when Britain leaves the European Union, allowing it to forge closer trade ties with the world's biggest economy.
While inspecting the guard at Windsor, Elizabeth appeared to give direction to Trump but then the president abruptly halted and Elizabeth was forced to walk around him.
"I didn't criticise the PM", Trump said at a press conference at the prime minister's official retreat in Chequers on Friday afternoon. That will be up to her to say.
The news that Trump disrespected the Queen comes after he was greeted by large scale protests in London ahead of his visit.
The president and his wife were greeted by the Guard of Honour, which gave a royal salute while the US national anthem was played.