Mr. Trump’s swing through Europe is meant to mark the 75th anniversary Thursday of the pivotal U.S.-led allied invasion of Normandy in World War II, yet there is a bitter undercurrent to the pomp and merrymaking.
As Mr. Trump arrived, British leftists were directing insults and protests at the president.
Labour Party leader Jeremy Corbyn boycotted the state banquet at Buckingham Palace in Mr. Trump’s honor.
Leftists were planning to hold a massive street protest Tuesday in central London against Mr. Trump’s visit. Mr. Corbyn said the protests are “an opportunity to stand in solidarity with those he’s attacked in America, around the world and in our own country — including, [London Mayor] Sadiq Khan.”
British Foreign Secretary Jeremy Hunt, who greeted Mr. Trump upon his arrival on Air Force One, said the Labour Party was trying to use the protests to distract from its own domestic scandals.
“What is really inappropriate is for anyone to boycott a visit by the president of the United States,” Mr. Hunt said on the BBC. “Really and truly, I think British people are going to be looking at this and saying, you know, when the president of the United States, our closest ally, comes to the U.K. on a state visit, we should be making him feel incredibly welcome on this, the 75th anniversary of D-Day.”
Kate Hoey, a Labour Party member of Parliament, said she was “saddened by the hysterical reaction” by some in her party to Mr. Trump’s visit.
“A democratically elected president of our closest ally should be welcomed whether we agree with his views or not,” she tweeted. “[Her Majesty] The Queen shows the world the nature of the U.K.”
Mr. Trump wasn’t afraid to rumble in the muck. He tweeted insults at Mr. Khan, a longtime critic, moments before Air Force One touched down.
“He is a stone cold loser who should focus on crime in London, not me. Kahn reminds me very much of our very dumb and incompetent Mayor of NYC, [Bill] de Blasio, who has also done a terrible job — only half his height,” Mr. Trump tweeted.
Trade tensions also simmered beneath the surface.
The British government is essentially rudderless, with Conservative Prime Minister Theresa May stepping down Friday because of her three-year failure to craft a plan for leaving the European Union.
Thirteen candidates are seeking to replace her. They include front-runner Boris Johnson, a former foreign secretary, and Brexit Party founder Nigel Farage, who is pushing for the U.K. to leave the EU without a deal Oct. 31.
Mr. Trump probably will be thrown into the debate at a joint press conference with Mrs. May on Tuesday.
The president supports the split from the EU and said Mr. Johnson would do an “excellent” job as prime minister. The president is also eager to forge a new trade deal with the U.K. that wouldn’t be bound by EU rules that he considers unfair to the U.S.
“They want to do trade with the United States, and I think there’s an opportunity for a very big trade deal at some point in the near future,” Mr. Trump said as he began his trip.
David Henig, a former U.K. trade negotiator, tweeted that “the U.S. number one goal for a U.K. trade deal is to move us away from the EU rule-set towards the U.S. one.”
Mr. Trump, for one, is optimistic.
“Big Trade Deal is possible once U.K. gets rid of the shackles,” he tweeted. “Already starting to talk!”