Trump and Charles greet each other warmly as the king begins a day of diplomacy in Washington

The royal visit comes at a challenging moment for U.S.-U.K. relations but is intended as a celebration of America's 250th anniversary of independence from Britain. In his welcome remarks, Trump highlighted the shared history between the two countries and sought to draw a line from King John's sealing of the Magna Carta in 1215 to the American Revolution.

“American patriots today can sing, ‘My country, ’tis of thee, sweet land of liberty,’ only because our colonial ancestors first sang, ‘God save the King,’” Trump said.

The two leaders planned to huddle in the Oval Office for a meeting that was closed to the public, reducing the potential for the freewheeling, sometimes controversial meetings with foreign officials that have become routine during Trump’s second term.

Charles will later address the U.S. Congress, only the second monarch to do so. His mother, Queen Elizabeth II, delivered a similar speech in 1991 highlighting the historic ties between both countries and the importance of their democratic values, themes Charles will likely reinforce on Tuesday. Such addresses are an opportunity afforded to only the most prominent world leaders, including Pope Francis, Václav Havel and Winston Churchill.

King's most extensive public remarks may come during congressional address

The congressional speech will likely mark the most expensive public remarks Charles will deliver during his four-day visit to the U.S. He's expected to address the Saturday shooting at the White House Correspondents’ Dinner in a sign of solidarity and support.

He will also acknowledge tensions that have surfaced between Trump and British Prime Minister Keir Starmer, noting that the two countries have not always agreed but have always found ways to come together.

Trump’s up-and-down relationship with Starmer has taken a particularly sour turn over the past several months as the Republican president has sought to rally international support for the war in Iran. Trump criticized Starmer, who has largely resisted his overtures, by saying “this is not Winston Churchill that we're dealing with.”

Trump has also imposed tariffs on the U.K. and warned of additional levies despite a Supreme Court ruling earlier this year that has made such unilateral moves more challenging. Trump threatened just last week to slap a “big tariff” on the U.K. if it doesn't scrap a digital services tax on U.S. technology companies.

Trump has more broadly challenged the traditional trans-Atlantic alliance with efforts to annex Greenland and threats to walk away from NATO. He has repeatedly imposed tariffs on and taunted Canada, a member of the British Commonwealth.

House Democratic leader Hakeem Jeffries of New York blamed Republican policies on Monday for straining the U.S.-U.K. relationship.

“Hopefully, the king’s visit is going to go a long way toward repairing the damage that this administration has done to one of our most important allies in the world,” Jeffries said.

Meanwhile, Charles has faced some calls on Capitol Hill to meet with victims of Jeffrey Epstein while he is in the U.S. There's no indication that he will do so even as the scandal involving the convicted sex offender has ensnared his brother, who was arrested in February over misconduct allegations, which he denies.

Rep. Ro Khanna, a California Democrat who has been a leader of the push on Capitol Hill for a reckoning over Epstein, said he was told by the British ambassador to the U.S. that there would be an acknowledgment of the survivors during the congressional address.

Charles and Camilla arrived at the nation's capital on Monday and held a tea with the president and first lady Melania Trump. The royal couple will continue their U.S. trip later this week with stops in New York City and Virginia.

Associated Press writers Stephen Groves in Washington and Danica Kirka in London contributed to this report.