Donald Trump is expected to meet the Queen when he makes his long-awaited visit to the UK on Friday July 13, according to reports.
The US president has been warned to expect protests during the controversial trip, which will be a “working visit” rather than a full-blown state occasion.
One element of contention is whether he will meet the Queen, an occasion usually associated with state visits.
Buckingham Palace, Windsor Castle and Balmoral have been tipped as locations for the royal encounter.
Meanwhile the visit will provide Theresa May with an opportunity to highlight the importance of the “special relationship” between the UK and US – and push for the prize of a trade deal after Brexit.
But the outspoken and unpredictable president will face mass protests from critics of his policies and behaviour.
In a sign of the difficulties in dealing with the Trump White House, Number 10 had hoped to co-ordinate releasing details of the trip, but the president’s press secretary Sarah Sanders slipped out the information first during a “take your child to work day” event.
The Prime Minister said: “I am looking forward to welcoming President Trump to the United Kingdom for a working visit on July 13.”
Downing Street said further details of the visit will be set out “in due course”.
London Mayor Sadiq Khan, who has clashed with the president over the response to a terror attack in the capital, said: “(Mr Trump will) … no doubt see that Londoners hold their liberal values of freedom of speech very dear.”
Even supporters of Mr Trump’s visit have urged him to stay away from London in an effort to avoid mass demonstrations.
In a letter to the US President, six conservative groups recommend he should instead focus his visit on his “ancestral home” of Scotland, including a meeting with the Queen at Balmoral.
Plans for a working visit to the UK in 2018 were announced when Mr Trump met Mrs May at Davos in January.
The July 13 date follows the Nato summit which the president is due to attend in Brussels on the preceding days.
Mr Trump cancelled a planned trip to London to open the new US embassy in Vauxhall earlier this year, complaining the move to an “off location” south of the Thames had been a “bad deal”.
The expectation of demonstrations is also believed to have played a part in the postponement of a state visit mooted for 2017.
That trip – which would involve lavish ceremonies and a stay with the Queen at Buckingham Palace – has been put off indefinitely, though Number 10 insists the invitation stands.
Mr Trump, whose mother was born on the Isle of Lewis, made frequent visits to Scotland before becoming president.
His last trip came during the presidential campaign in June 2016, when he visited his golf resorts.