WATCH Trumps, John Bolton Get Booed Outside of Downing Street By Protesters

Donald Trump's eldest daughter, Ivanka, and his national security adviser John Bolton have failed to enjoy a warm reception from Londoners.

Some boos and heckles were audible as the two left 10 Downing Street on Tuesday.

The walk-out was livestreamed on Fox & Friends, with host Brian Kilmeade insisting that the boos in fact were meant for "tough guy" John Bolton.

"It's not for Ivanka, it's for John Bolton and he loves it", Kilmeade said. "He pretty much is looked at as somebody, as the tough guy in the administration, and he loves that label".

President Trump and outgoing British Prime Minister Theresa May, trailed by US First Lady Melania and May's husband Philip, faced a similar reaction from the crowd minutes later.

At a press conference that followed, Trump downplayed the size of the protests.

"There were thousands of people on the streets cheering", Trump said. "And then I heard that there were protests. I said, 'where are the protests? I don't see any protests'".

He went on to concede that he "did see a small protest", but dismissed reports about mass protests as "fake news".

Earlier in the day, Trump arrived at the UK PM's residence for talks with Theresa May. He afterwards promised a "phenomenal" post-Brexit trade deal and praised relations with the UK as "the greatest alliance the world has ever known".

Meanwhile, campaign group Stop Trump UK said 75,000 people showed up in London on Tuesday for anti-Trump demonstrations, against the initial expectations of bringing together as many as 250,000 people.

The demonstrators flew the much-awaited "Trump baby" balloon that made its debut last year, as well as a huge talking "Dumping Trump" robot depicting the US president sitting on a toilet.