Protesters have been inflating a blimp made to look like a baby version of Trump, and are preparing to fly it over Parliament during his visit.
Trump added that the U.K.is a "pretty hot spot", given the recent upheaval in the government there.
The US president has angered many in Britain in the last two years with a series of actions and pronouncements.
The reason: demonstrations are planned against President Donald Trump, in London, as well as Windsor, Bristol, Newcastle, Leeds, Cambridge, Cardiff, Glasgow and the west coast of Scotland, where Trump has a golf course.
Mr. Trump has been quick to criticize British society, telling an NRA convention in May that the British didn't have guns but had so much knife crime that one hospital was like a military war zone with its floors awash with blood - a statement quickly rebutted by British physicians and politicians.
Trump will depart the North Atlantic Treaty Organisation summit in Brussels on Thursday afternoon local time and head to London for a greeting ceremony.More news: Peter Strzok Spins Conspiracy Theory in House Testimony: Investigating Me Helps Putin
"I think they like me a lot in the UK", Trump said in Brussels.
Last month, Labour member of Parliament Gavin Shuker ran down a list of objections to Trump: the separation of migrant families and detention of children; the USA departure from the United Nations' Human Rights Council; the US president's praise for North Korean leader Kim Jong Un.
Trump is on a "working visit" rather than a full state occasion.
While the many thousands are expected to line the streets and protest against Trump, politicians have become involved too.
"I'm excited to welcome the President of the United States", says Drew, who's 21.
Trump's visit to the United Kingdom, the 12th US President to make such a tour, comes amid what he described as "turmoil" for the United Kingdom government, as Prime Minister May faces down rebellion from within her own party over her Brexit strategy.More news: Guendouzi: Arsenal was an easy decision
Tomorrow, May and Trump will visit an unnamed defence site to view a demonstration of UK military capabilities, as a showcase of integrated UK-US military training. Some plan to stage an "all-night noise protest" outside the barricades surrounding Winfield House later Thursday, with those attending urged to "bring pots, drums and vuvuzelas".
Ignoring all diplomatic niceties, the convention-shredding U.S. president set up the four-day visit with a rebuke of May as she battles to stop her government falling apart over Brexit. "It's really kind of irrelevant to what we're trying to do, and doesn't express the opinion of the British people that I've met", he told the BBC's Today programme.
Trump will depart Britain Friday for Finland to prepare for a summit with Russian President Vladimir Putin Monday in Helsinki.
Like this go-round, protesters promised widespread backlash back in February amid the president's plans to travel to London for the grand-opening of a new US embassy.
The two leaders will hold talks the following day at Chequers, the 16-century manor house which is the prime minister's official country residence.More news: Serena Williams vs Julia Goerges, Wimbledon 2018 semi-final
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