When King Charles III and Queen Camilla of Britain arrived at the White House for a state visit on Monday afternoon, President Trump pointed to a large hole where the East Wing used to be before taking his guests inside for tea and a private audience with the White House beehive.

Presidents use state visits as an occasion to showcase the best of American culture — and, in this case, perhaps, subtly highlight the resilience of a people who, 250 years ago, rose up and wrested themselves from a king’s control.

The shooting over the weekend at the White House correspondents’ dinner has featured the darker side of the United States at a time when Mr. Trump is supposed to be showcasing America’s 250th birthday for the British royalty. For a moment over the weekend, it was unclear if King Charles would travel to Washington at all, before he reassessed and ultimately committed to his plans for a four-day visit to Washington, New York and Virginia.

Threats of violence against public figures in the United States have accelerated so much that administration officials have moved to live in military installations out of fear for their safety. The visit has also highlighted the nature of a president who has opted, time and time again, to show aggression rather than diplomacy when on the world stage.

Shortly before the arrival of the king and queen, Karoline Leavitt, the White House press secretary, took the podium inside the briefing room to admonish Mr. Trump’s enemies for creating “left-wing cult of hatred against the president,” as she fielded questions and assigned blame for the conditions that caused a gunman to rush toward a ballroom where Mr. Trump was scheduled to address members of the Washington news media on Saturday night.

She also addressed the rampant skepticism and conspiracy theories questioning the events that led to them: “Hopefully people will believe the truth rather than the lies,” she said.

And Mr. Trump, who appeared relatively unfazed after the shooting on Saturday evening, spent Monday returning to form, taking to the presidential Truth Social account to attack a late-night television host and share pictures of his latest construction project, which entails cleaning large amounts of goose excrement out of the reflecting pool in front of the Lincoln Memorial.

This all complicates the unofficial diplomatic mission that lies ahead for King Charles, who will try to soothe ruffled feathers in a relationship between Mr. Trump and Prime Minister Keir Starmer that has gone south rapidly over the last several months.

Early in Mr. Trump’s second term, Mr. Starmer tried heaping praise on the president, even once bending down to pick up papers the president dropped on the ground. But more recently, the prime minister’s decision not to join the U.S.-Israel war in Iran has darkened Mr. Trump’s mood. The president has called Mr. Starmer a coward for not entering the fight and has belittled the British navy.

More recently, a memo drafted at the Pentagon suggested that the Trump administration could stop supporting British sovereignty over the Falkland Islands.

The conflict has also strained the so-called “special relationship” between the two countries. Officially, the king is above all of that, and few people on either side of the Atlantic expect the monarch to engage in a war of words with Mr. Trump. But privately, many British officials hope that this week’s visit could help charm the president into softening his tone.

While they are in the United States, the royal couple will be under protection by the Secret Service, at a moment when there are new questions about the agency’s ability and capacity to protect public figures in an age of rising threats.

“In some ways I am surprised that the Secret Service would say, ‘Yes, come ahead, King Charles, it’ll be fine,’ and it’s a little bit surprising that he wanted to come,” said Barbara Perry, a presidential historian at the University of Virginia’s Miller Center. “On the other hand, this will be a way for him to prove that we have this bond and at that, despite what happened on Saturday night, he is willing to come and possibly risk his life.”

The king and queen hosted Mr. Trump for a state visit last September, treating the president to a royal banquet and an overnight stay in Windsor Castle. Mr. Trump, a former hotelier, is looking to return the lavish favor.

White House officials were initially planning for the king and queen to stay in the White House residence, according to two officials familiar with the planning, where King Charles’s mother and father, Queen Elizabeth II and Prince Philip, once stayed during a visit in 1957. In the end, the royals have opted to stay across the street at Blair House, which is larger and reserved for visiting dignitaries.

The schedule released by the White House ahead of the visit illustrated how sequestered the Trumps have become amid heightened fears about their safety. For past state visits, Mr. Trump has traveled the country — or at least left the White House — with his guests. In 2018, the Trumps took a tour of Mount Vernon with President Emmanuel Macron of France and his wife, Brigitte Macron, and Mrs. Trump took Ms. Macron to view art at the National Portrait Gallery. In 2019, Mr. Trump visited a factory in Ohio with Scott Morrison, the former Australian prime minister.

This week, the Trumps are not leaving the complex, which Mr. Trump has altered by tearing down the East Wing, festooning the Oval Office with gold and paving over the Rose Garden. Outside of the royal couple’s quarters at Blair House, the bricks in Lafayette Park have been torn out — too easy for protesters to pick them up throw them, the president has said. The fountains in the park have been turned on.

Rather than leaving the White House, the Trumps have opted instead to host “thousands of guests on the South Lawn,” a group that includes members of Mr. Trump’s cabinet. Mrs. Trump will host Queen Camilla and American students at the White House Tennis Pavilion, where the group will use “A.I.-enabled glasses to learn about American history,” according to a release from the White House.