Donald Trump mistakenly referred to King Charles III by his former royal title as he prepared to leave for his state visit to the United Kingdom on Tuesday, 16 September.
The US president described His Majesty as an "elegant gentleman" and his "friend" as he set out what he hoped to achieve from the trip.
Speaking as he was leaving the White House, Mr Trump said: "Primarily it's to be with Prince Charles and Camilla. He's [a friend] of mine for a long time, long before he was king... I think he represents the country so well.
"He's such an elegant gentleman.”