King Charles was filmed at the start of the first weekly audience with the prime minister with the King addressing her with "Dear oh dear" as she was welcomed into the room.
It is the third time the King has met the Prime Minister Liz Truss, with the pair officially meeting for the first time at Buckingham Palace on September 9, the day after the Queen died.
However, yesterday evening was the first of Charles and Ms Truss's private audiences.