Donald Trump will meet the Queen when he visits Britain next month, the US ambassador to the UK has told Sky News.
The president is due in Britain for a working visit on Friday 13 July – his first to the country since being elected in 2016.
It is not a state visit with all the pomp and ceremony that comes with that, so the pair would not necessarily need to meet.
But ambassador Robert Wood Johnson said that while plans have not yet been finalised, they will involve the president meeting Her Majesty.
Mr Johnson was asked by Sky's Kay Burley whether the itinerary would include seeing the Queen.
He replied: "Yes, yes, I mean he has to see the head of state. Putting his foot on British soil, it's job one, it's very important, very symbolic.
"Meeting Her Majesty is the most important thing, because she's the head of state, and from then on, it'll be what the president wants to do."
It is thought the president will meet the Queen at Windsor Castle, as it will be closed to the public on 13 July.
He is also expected to have talks with Theresa May during his time in the UK.
Anti-Trump protests are expected over his administration's controversial policies on immigration, including separating migrant children from parents who crossed the border illegally from Mexico.
The youngsters have been pictured being held in cages, sparking worldwide outrage.
Mrs May has criticised the policy, saying she finds the pictures "deeply disturbing".
Pro-migrant campaigner Lord Dubs has told Sky News he believes the prime minister should axe Mr Trump's trip
He said: "I think Theresa May should cancel Trump's visit to the UK… we have to stick by our principles."
Mr Trump had been expected to open the new US embassy in London in February, but cancelled the visit as he criticised the Obama administration's choice of location.
'I think Theresa May should cancel Trumps visit to the UK… we have to stick by our principles' says Lord Dubs after Trump has defended footage of children kept in cages at a migrant camp in the US pic.twitter.com/xV9gGvt5RL
— Sky News (@SkyNews) 20 June 2018
Mrs May invited him for a state visit when she travelled to the White House in January 2017.
Following the invitation, more than 1.8 million Britons signed a petition against the visit.
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The petition said: "He should not be invited to make an official state visit because it would cause embarrassment to Her Majesty the Queen."
Sky News understands the president is exploring the possibility of staying here for longer so he can play golf.