Queen Elizabeth has met with three other US presidents at Windsor Castle, including Barack Obama, George W. Bush and Ronald Reagan.
Unsurprisingly, the meeting had everybody talking on social media, with a clip of the president stopping abruptly in front of the Queen doing its rounds online.
"These demonstrators gathering here on Parliament Square see him as a bigot, as a racist, as a xenophobe, as a misogynist", Barker said.
Man who harassed woman over Puerto Rico shirt charged with hate crime
In the part of the video that went viral, Officer Connor's voice is never heard and he apparently does nothing. The officer can then be seen talking to the man who gesticulates back and tells him to "shut the f*** up".
"What is interesting is Trump is not criticising mayors of those cities, but he is criticising me", he told the BBC's Today programme. I haven't been there in a long time. Protest organizers said on their campaign website they want to "make sure [Trump] knows that all of Britain is looking down on him and laughing at him" during his visit.
United States President Donald Trump said he doesn't feel welcome in London, and he blames that in part on Mayor Sadiq Khan.
"The idea that we restrict freedom of speech, the right to assemble, the right to protest because somebody might be offended is a slippery slope", he told BBC radio, adding that a protest to welcome Trump was also planned.
Before the Sun interview was published, Ms May invoked Winston Churchill as she addressed Mr Trump and business leaders at a black-tie dinner at Blenheim Palace, the grand 18th-century country house which was the British World War II leader's birthplace. As he said in his interview with the Sun she "is a very good person" and he "never said anything bad about her".
"But having a special relationship means that we expect the highest standards from each other, and it also means speaking out when we think the values we hold dear are under threat".