By Nandita Bose and Patricia Zengerle
WASHINGTON, April 28 (Reuters) - Britain's King Charles will address the U.S. Congress on Tuesday with a message of unity between the United Kingdom and the United States, promoting the "special relationship" at a time of differences between the British government and President Donald Trump over the war on Iran.
Charles and Queen Camilla are on a four-day state visit to the U.S., steering clear of the political rifts between Trump and British Prime Minister Keir
Starmer while underscoring the deep ties forged between Britain and its former colony over the 250 years since independence.
The king's address, scheduled to begin at 3 p.m. EDT (1900 GMT), will be only the second by a British sovereign to the U.S. Congress, after his mother Queen Elizabeth II spoke to both houses in 1991.
It is a central event of the state visit - the most high-profile of Charles' reign - and will be followed by a state dinner on Tuesday night.
The king’s speech is expected to last about 20 minutes, a palace source said, and touch on issues including NATO, the Middle East and Ukraine. While written on the advice of the British government, much of the language and tone comes from Charles himself, the source said.
Its central message will focus on challenges facing both nations, stressing that the two countries can promote international security and prosperity by defending their shared values.
Despite periodic differences, the king will say, “Time and again, our two countries have always found ways to come together," and will describe the partnership as “one of the greatest alliances in human history," the source said.
Trump, a vocal admirer of the British royal family who often calls Charles a "great man," has nonetheless clashed with Starmer's government.
Starmer hopes the visit will shore up the transatlantic relationship, which has been strained in recent months.
The long-planned visit has unfolded against tensions over the U.S.-Israeli war on Iran, after Trump criticized Britain for declining to support the offensive.
Although Trump has eased his criticism in recent days, an internal Pentagon email outlining how Washington might review its position on Britain's claim to the Falkland Islands has raised concern across the Atlantic.
The visit began on Monday when Charles and Camilla met Trump and first lady Melania Trump for a private tea at the White House, followed by a garden party at the British ambassador’s residence, where they mingled with media leaders, Washington socialites and U.S. officials.
On Wednesday, the royals will be in New York City to commemorate those killed in the attacks of September 11, 2001, and the trip concludes in Virginia on Thursday with the king meeting people involved in conservation, reflecting his long-standing environmental advocacy.
(Reporting by Nandita Bose and Patricia Zengerle in Washington; Additional reporting by Michael Holden in London; Writing by Daniel Trotta; Editing by Christian Schmollinger)
