King Charles III visited the White House amid strained UK-US relations due to tensions over the Iran war. He was greeted by Trump and Melania Trump, and later attended a garden party at the British Embassy. The visit marks Charles's first state visit since becoming king and comes with the backdrop of political tensions, including Trump's criticism of UK Prime Minister Keir Starmer. The shadow of Prince Andrew's controversies also looms over the visit. The king is set to address Congress, a rare event for a UK monarch.