King Charles III will meet Trump and address Congress in a bid to spotlight UK-US ties

Such addresses are an opportunity afforded to only the most prominent world leaders, including Pope Francis, Václav Havel and Winston Churchill. It will likely mark the most extensive public remarks Charles will deliver during a four-day visit to the U.S. that's intended to celebrate the country's 250th anniversary of independence from Britain.

House Speaker Mike Johnson, R-La., became the first sitting leader of his chamber to address the U.K. Parliament earlier this year. He attended a garden party with the king in Washington on Monday and said he told him he would be “well received” in Congress.

The king, accompanied by Queen Camilla, will begin his day with a meeting at the White House with President Donald Trump. The Oval Office encounter offers the potential for the freewheeling, sometimes controversial meetings with foreign leaders that have become routine during Trump's second term.

But it will be closed to the public, and, given the expressly apolitical nature of the British monarch and Trump's fondness for the royal family, the likelihood of an awkward meeting may be reduced. Trump will host Charles on Tuesday evening for a state banquet at the White House.

The visit comes at a challenging moment for U.S.-U.K. relations. Trump’s up-and-down relationship with British Prime Minister Keir 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.

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, D-Calif., urged the king over the weekend to at least address the issue during his congressional speech.

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.

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 writer Stephen Groves in Washington contributed to this report.