Donald Trump has insisted the US-UK relationship is “the highest level of special”, hours after he told the Sun Theresa May's Brexit plan would kill a trade deal between the countries.
Speaking alongside the PM, Mr Trump said Brexit was an “incredible opportunity” and “whatever” the UK did after it left the EU was “OK with me”.
Mrs May said they had discussed plans for an “ambitious” trade agreement.
Thousands of people are protesting in central London against his visit.
A large balloon, portraying the president as a baby, has been floated in Parliament Square as part of the demonstrations. Other protests are due to take place across the UK on Friday and Saturday.
Mr Trump's first visit official visit to the UK as president is taking place in between the Nato summit and a meeting in Helsinki with Russian leader Vladimir Putin.
The president and first lady are travelling to Windsor to meet the Queen, before flying to Scotland to spend the weekend at Mr Trump's Turnberry golf resort.
