King Charles III will deliver a rare address to a joint session of the US Congress on Tuesday, where he is expected to call for “reconciliation and renewal” in relations between the United States and the United Kingdom amid tensions over the Iran war.The address, the first by a British monarch since Queen Elizabeth II’s speech in 1991, is expected to last about 20 minutes and will focus on strengthening the long-standing alliance between the two countries despite persisting political differences.King Charles III, accompanied by Queen Camilla, arrived at Joint Base Andrews in Maryland on Monday, where he was greeted by US protocol chief Monica Crowley and British Ambassador Sir Christian Turner, as well as a ceremonial welcome with the national anthem. She later met Donald Trump and Melania Trump for tea at the White House, before attending a garden reception at the British Embassy, AFP reports.The visit marks the 250th anniversary of US independence and is being seen as a soft power effort by London to stabilize relations at a delicate moment. Security has been tightened in Washington following the shooting at a White House dinner attended by Trump, with King Charles III expected to make a brief mention in his speech expressing sympathy.His address came against the backdrop of tensions between Trump and Keir Starmer after Britain refused to support US-led military action against Iran. Trump publicly criticized Starmer, saying that their relationship was “not good at all.” He has also repeatedly criticized the British Prime Minister for his opposition to the war, as well as his government’s immigration and energy policies. Starmer has defended the state visit while publicly criticizing the war.According to royal aides, King Charles III would embrace such differences while insisting on continuity in the partnership, noting that “time and time again, our two countries have always found ways to come together.” He is expected to describe the alliance as “one of the greatest alliances in history” and underline the need for unity in the face of global challenges.King Charles III will stress that defending democratic values is “vital to freedom and equality” and will advocate for cooperation on shared priorities, including NATO, the Middle East, Ukraine and the AUKUS treaty. They are also expected to highlight the values of tolerance and peace, describing the transatlantic alliance as having a duty to promote “generosity of spirit” and mutual understanding.The British monarch will be given a full ceremonial welcome at the White House on Tuesday, including a 21-gun salute and inspection of troops before his address and a state dinner hosted by Trump. The royal couple will visit New York on Wednesday, including a visit to the 9/11 memorial, before departing for Bermuda on Thursday.