Prince William dons military uniform as he stands in for King Charles during US visit

Prince William donned a military uniform during a visit to RAF Valley, a Royal Air Force station on the island of Anglesey, Wales.

Kensington Palace released multiple photos of the future king from the visit with a brief statement on social media.

"Always a pleasure returning to RAF Valley, even more so as Royal Honorary Air Commodore," said the Prince of Wales.

William's visit came hours after his father, King Charles III, landed in the US with wife Queen Camilla for his first visit to the country as the British monarch. 

In the absence of the king, Prince William and other senior members of the British royal family stand in for the monarch.

For specific constitutional duties that require king's  presence in the UK, Counsellors of State step in. Day-to-day constitutional stuff that can’t wait is handled by Counsellors of State, mainly Prince William in practice.