Prince Harry donned an apron to help serve barbecue to competitors, volunteers and their families at the Warrior Games in San Antonio over the weekend.
The Duke of Sussex also participated in medal ceremonies, presenting awards to winners of the competition.
Event organisers expressed their appreciation on Facebook, stating: "We were honoured to have Prince Harry, Duke of Sussex, out to support our wounded, ill, and injured service members during Cycling and Wheelchair Basketball.
"On Day 2 of the Warrior Games, he brought energy, encouragement, and support to our competitors' recovery journeys."
Prince Harry has been serving barbecue in an apron and gloves
|FACEBOOK/@WARRIORGAMES
The Warrior Games are credited with inspiring Harry's own Invictus Games, which will take place in Birmingham next year.
The Duke of Sussex spent his weekend in Texas making several unexpected public appearances while his royal relatives gathered in London for one of the monarchy's most significant annual occasions.
Shortly after working members of the Royal Family assembled to mark King Charles's official birthday, Harry was spotted at the NBA finals before travelling to the US Government's Warrior Games, an event supporting wounded, injured and ill military personnel.
The duke has now been absent from Trooping the Colour for four consecutive years, with his Texas engagements coinciding directly with Saturday's ceremonial celebrations in the capital.
King Charles marked his official birthday with the traditional Trooping the Colour ceremony, a spectacular showcase of British military precision and pageantry in the capital | GETTYHarry attended game five of the finals series between the San Antonio Spurs and New York Knicks, sitting just a few rows from the court alongside NBA Commissioner Adam Silver.
The duke was accompanied by JP Lane, a US Army veteran who has received the Purple Heart.
His wife Meghan and their children, Prince Archie and Princess Lilibet, did not join him for the match.
The evening concluded with the Knicks triumphing 94-90, securing their first NBA championship in over five decades.
Prince Harry arriving at the San Antonio Spurs and the New York Knicks game during the 2026 NBA Finals at Frost Bank Center | REUTERSLATEST ROYAL NEWS:
Prince Harry unexpectedly turned up at the NBA Finals in San Antonio, witnessing the New York Knicks secure their first championship in over five decades
| GETTYSince relocating to the United States in 2020, Harry and Meghan have frequently attended sporting fixtures, including February's NBA All-Star Game.
Meanwhile in London, King Charles marked his official birthday with Trooping the Colour, a ceremony displaying the British Army's ceremonial expertise.
The Princess of Wales attended alongside the Queen and thousands of spectators at Horse Guards Parade in Whitehall.
Prince George, Princess Charlotte and Prince Louis, aged 12, 11 and eight respectively, observed their grandfather from the first-floor window of the Duke of Wellington's former office, which overlooks the parade ground.
Crowds lined The Mall to witness the Royal Family's carriage procession from Buckingham Palace, with the King and Queen Camilla travelling at the centre of a Sovereign's Escort from the Household Cavalry Mounted Regiment.