US President Donald Trump has said he could "work with anybody" in No 10 - nine days ahead of a general election.
Speaking on a three-day visit to the UK, Mr Trump said he would "stay out of the election", that he was a "fan of Brexit" and he thought PM Boris Johnson was "very capable".
Mr Trump is in the UK for a Nato summit being held in Watford on Wednesday.
He attended a reception hosted by the Queen at Buckingham Palace and later went to an event at Downing Street.
The US president's comments in a press conference came moments after he told reporters that he was staying out of the election on 12 December "because I don't want to complicate it".
What else has Trump said?
- The US wanted "absolutely nothing to do with" the NHS, when asked if it would form any part of future trade talks. He said he wouldn't touch it even if it was handed to his administration "on a silver platter", adding: "Never even thought about it, honestly"
- He himself was "a very easy person to work with"
- The passersby who tackled a man during a "terrible attack" on London Bridge on Friday did "an amazing job". He said: "I was very proud of those people who grabbed him", referring to Usman Khan who killed two people and injured three others before armed police shot him dead
- French President Emmanuel Macron was "very disrespectful" for suggesting Nato was "brain dead"
- On Prince Andrew stepping down from royal duties, he said: "I don't know Prince Andrew, but that's a tough story, it's a very tough story." The Duke of York has been facing questions over his ties to disgraced financier Jeffrey Epstein. Mr Trump met the duke on his last visit to the UK in June
Who is Trump meeting?
President Trump is visiting the UK to attend a Nato summit commemorating the 70th anniversary of the transatlantic organisation.
He had a breakfast meeting with Nato Secretary General Jens Stoltenberg at the US ambassador's residence in London.
Mr Trump held separate talks with French President Emmanuel Macron.
Later, Prince Charles and the Duchess of Cornwall were kept waiting for around 40 minutes before the US president and First Lady Melania Trump arrived at the prince's residence, Clarence House, for afternoon tea.
Mr Trump and his wife went on to join other Nato leaders and senior royals at a Buckingham Palace reception, hosted by the Queen.
The first couple later attended a reception at Downing Street with other world leaders.
It is unclear whether Mr Trump will hold a one-on-one meeting with Mr Johnson during his visit to the UK.
The US president said he would be meeting the British prime minister during his visit, adding: "I have meetings set up with lots of different countries".
Mr Johnson said he would be discussing Syria, Russia and China during discussions with Nato leaders.
Foreign Secretary Dominic Raab - who held a meeting with US Secretary of State Mike Pompeo - said arrangements for such bilateral meetings were "always quite fluid".
BBC diplomatic correspondent James Landale said the Conservatives' HQ is not keen on such a meeting "to avoid pictures that could be used by his (Boris Johnson's) opponents" in the upcoming general election.
Mr Johnson and Mr Trump did speak on Saturday, when Mr Trump expressed his condolences after the London Bridge attack.
There'll be an almighty shuddering sigh of relief reverberating around the walls of Downing Street. Because there was real apprehension in No 10 about exactly what the president might say. In fact, he's given Boris Johnson an almighty helping hand in this election.
Most importantly, we heard Donald Trump seeking to counter what has become one of the main attack lines of the Labour Party and Jeremy Corbyn during this campaign, that if you re-elect Boris Johnson he will ensure that the NHS is on the table in trade talks with the US.
And yet we heard Mr Trump being pretty unequivocal that he's not interested in the NHS, even if it was presented to him on a silver platter and also suggesting he didn't know why it was being raised as an issue, even though, in fact, it was Mr Trump who first raised it as an issue when he was here in June at a news conference saying everything should be on the table.
Be that as it may, I think Team Johnson will be mightily relieved that he has, as it were, provided them with a get-out-of-jail-free card to Labour claims that the NHS would be on the table.
What's been the reaction to his visit?
Labour leader Jeremy Corbyn, who called for Mr Trump to be treated "with respect and politeness" during his visit, wrote to Mr Trump ahead of his visit, demanding assurances that the NHS will be "off the table" in any post-Brexit US-UK trade talks.
Mr Corbyn told the BBC's Jeremy Vine show that he would seek assurances from Mr Trump at the Buckingham Palace reception later.
"I will say, look, welcome to this country. I hope you'll understand how precious our national health service is," he said.
"And in any future trade relationship with the USA, none of our public services are on the table, none of our public services are for sale."
Mr Trump has previously been criticised for voicing his opinions of British political leaders.
The US president was warned against getting involved in the upcoming general election by Mr Johnson last week.
Nigel Farage said it was "awkward" that his "friend", Mr Trump, had arrived during the election campaign, adding that he didn't intend to speak to him.
The Brexit Party leader said if there were "personal exchanges", they would be "purely personal" and he would keep them private.
Scotland Yard has said road closures will be in place in central London during the summit.
Protesters gathered in Trafalgar Square, before heading to Buckingham Palace ahead of the reception for Nato leaders.
BBC journalist Charlotte Gallagher, who was at the protest, said it was a real mixture of people "but they all had one thing in common - an intense dislike of President Trump".
"There were people with concerns about the future of the NHS, the Campaign for Nuclear Disarmament, while others were demanding the release of Julian Assange."
She said she also spoke to several US tourists who decided to come to the protest to show how unhappy they were with their own president.
The mother of teenage motorcyclist Harry Dunn was among the protesters. Mr Dunn's death has led to a diplomatic row between the US and UK after a suspect over his death returned to America, claiming diplomatic immunity.
Charlotte Charles said the response from other protesters outside the palace to her campaign for justice had been "heart-warming".
The Foreign Office said Mr Raab raised "UK concerns" about the case with his US counterpart at a meeting earlier.