Buckingham Palace has announced two major overseas trips for September, but one of them clashes with the US State visit.
It's been confirmed that the Duke of Edinburgh will visit Papua New Guinea, on behalf of the King, from 14 to 17 September, to attend celebrations marking the 50th anniversary of the country's independence from Australia.
Prince Edward will then travel to Japan, where he will be joined by his wife, the Duchess of Edinburgh, from 18 to 22 September, to celebrate the strong bilateral relationship between the UK and Japan.
Edward and Sophie will therefore miss US President Donald Trump's state visit to the UK from 17 to 19 September.
The King and Queen will host the President and First Lady Melania Trump at Windsor Castle during their visit, and usually many of the senior royals are involved in state visits.
Trip itineraries
In Papua New Guinea, Edward will attend a dawn flag-raising ceremony and a state dinner, to mark the occasion.
During the visit, on behalf of the King, the Duke will present new Regimental Colours to the First Royal Pacific Islands Regiment and confer 50th Independence Anniversary King's Medals, awarded to individuals who have made significant contributions to Papua New Guinea.
He will also visit the new National Court Complex and meet communities in Port Moresby. The trip will be Edward's first to Papua New Guinea.
In Osaka and Tokyo in Japan, the Duke and Duchess will undertake engagements on themes which resonate in both countries, including youth opportunity, sustainability and innovation, educating the next generation, and women in leadership.
During the visit, Edward and Sophie will visit the UK and Japanese Pavilions at EXPO 2025, Osaka, Kansai. As Japan's largest international event this decade, the aim is to bring together people and innovations from around the world to address global issues.
While the Duke has previously visited Japan in 2004, 1998 and 1996, this will mark the Duchess' first official trip.
Sophie will also travel to Alberta in Canada on 4 September, with a visit to the show jumping venue Spruce Meadows included in her programme.