Japan's Emperor Naruhito and Empress Masako are on a state visit to the United Kingdom and have attended a welcome ceremony in the capital London.

The Imperial couple were officially invited to the United Kingdom by King Charles.

They were greeted by Prince William at their hotel on Tuesday, then traveled with him to the headquarters of a cavalry regiment that helps guard the British Royal family.

Then, along with King Charles and Queen Camilla, they proceeded by carriage to Buckingham Palace via a one-kilometer-long road known as the Mall.

The Emperor and Empress will attend a welcome luncheon with members of the Royal family at the palace.

Later in the day, the Imperial couple will return to Buckingham Palace for a banquet hosted by the King and Queen.

This is the third state visit to the United Kingdom by a Japanese Emperor and Empress. Emperor Showa and Empress Kojun made a state visit in 1971. Emperor Emeritus Akihito and Empress Emerita Michiko visited in 1998, when they were Emperor and Empress.