A baby-shaped Trump balloon is expected to fly over Parliament on Friday morning.
Nick Hurd, Britain's policing minister, told parliament police expected more than 100 protests across the country, including two large demonstrations in London on Friday, and there were robust and proportionate plans in place.
In London, we speak with Sheila Menon, social justice activist and one of the organizers behind the Trump baby blimp.
On Friday, May and Trump will hold talks on Brexit, relations with Russian Federation and trade ties at the prime minister's Chequers country residence followed by a press conference.
The 6m high balloon shows Mr Trump as a giant baby in a nappy with his trademark blonde hair.
Despite the welcome from May, many Britons are opposed to Trump's visit.
In the Tuesday memo, the U.S. Embassy in London alerted citizens to the "numerous demonstrations" that could "attract large crowds" that may be less than agreeable toward Americans.
Widespread protests opposing President Trump's stay begin Thursday evening and continue through Friday night.
Mr Morgan, the forthright journalist and broadcaster, hit back and questioned why the London mayor had not been so vocal over the visit of controversial Turkish President Recep Erdogan.
"And me mate said "If you call it the Trump Arms I'll organise the party".
Prime Minister May has abundant reasons to seek a close relationship with Trump - not least, the United States will be an even more vital trade partner once Britain leaves the European Union next year - but it is an uneasy embrace, given her opposition to many of his key policies.
Similar protests are planned on Thursday evening outside the United States ambassador's home at Regent's Park and in Scotland when Mr Trump visits on Saturday.
"There is definitely a sense that Britain needs America more because of Brexit", said Bronwen Maddox, head of the Institute for Government, a think tank. Later, Trump will go to Windsor Castle for tea with 92-year-old Queen Elizabeth.
Mr Smyth, who is originally from Ireland, said Trump fans had been given a bad rap, and there had been lots of support for the pub's temporary renaming.
The prime minister will host him for dinner at Blenheim Palace, the ancestral home of Churchill near Oxford, and then for the meeting at the prime ministerial country retreat Chequers, north of London.
While Mr Johnson may now be a backbencher, Mr Trump said he hoped he would still see the former foreign minister - another blow to the fragile position of Mrs May.