"That's certainly up to the people, not up to me", said Trump.
We understand the president's time in Scotland is planned as a personal, private visit between other engagements with no official meetings.
"I've always liked writing amusing songs and he just lends himself to them".
"Our trade and investment relationship is unrivaled - we are the largest investors in each other's economies and every day a million British people go to work for US companies in the United Kingdom and a million Americans go to work for United Kingdom companies in the US", May said.
"Boris Johnson's a friend of mine, he's been very nice to me, very supportive and maybe I'll speak to him when I get over there".
Mr Trump arrives Thursday afternoon following a North Atlantic Treaty Organisation summit in Brussels and largely avoids the capital's centre and the protesters.
Some 77 per cent of Britons have an unfavourable view of Trump, according to a poll by YouGov with 1,648 respondents.
London Mayor Sadiq Khan, who signed off on the so-called "baby Trump" blimp, defended the decision Thursday, arguing the protests were not anti-American but emblematic of free speech.
Later, Trump will take tea with Queen Elizabeth II at Windsor Castle, a home to the royals for 1,000 years, part of a tour created to keep him away from protesters.
After London, he will travel to Scotland and then onto Helsinki to meet with Russian president Vladimir Putin.
Similar protests are planned on Thursday evening outside the USA ambassador's home at Regent's Park and in Scotland when Mr Trump visits on Saturday.
His "America First" policies, including the decision to pull the United States out of the Paris climate accord and the nuclear deal with Iran, have brought him into conflict with Britain's leaders over issues of real substance.
A small demonstration is expected to take place near Blenheim Palace in Oxfordshire on Thursday, the venue for Trump's black-tie dinner with Prime Minister Theresa May.
Churchill spent three weeks at the White House, cementing his close ties with Roosevelt and forming the basis for future relations between the USA and Great Britain.
After spending the night at the United States ambassador's official residence in Regent's Park, London, the U.S. president will join the Theresa May at a military base on Friday to view a joint counter-terrorism exercise involving UK and USA special forces.