It went unspoken by the White House that Mr. Johnson has been desperate to keep Mr. Trump at a distance in an election where the American president is now seen as radioactive to many of his supporters. “What we don’t do traditionally as loving allies and friends, what we don’t do traditionally, is get involved in each other’s election campaigns,” Mr. Johnson said in a radio interview last week.

Whether Mr. Trump is able to heed the “stay away” signals Mr. Johnson has been waving in his face remains to be seen.

If he does, it would mark a big departure from his style on previous visits. Mr. Trump’s interview with The Sun defined his awkward trip last year to Britain, where he was forced to dismiss his own, recorded interview as “fake news” while standing next to Mrs. May at a news conference.

The White House press secretary, Stephanie Grisham, said on Friday there were currently “no plans” for a follow-up interview with The Sun, a tabloid owned by Rupert Murdoch.