Japan's Emperor Akihito and Empress Michiko on Thursday left Thailand, the final leg of a three-nation Southeast Asia tour.

The couple joined royals from 24 nations for celebrations Monday and Tuesday marking the 60th anniversary of Thai King Bhumibol Adulyadej's accession to the throne. The 78-year-old king is the world's longest-reigning monarch.

Akihito and Michiko also visited Singapore on their first state visit to the city state, which coincided with the 40th anniversary of the start of diplomatic relations between Japan and Singapore.

They also travelled to Malaysia, their second trip there since Akihito, 72, ascended to the throne in 1989.