Emperor Akihito and Empress Michiko will visit Saipan, a site of fierce fighting between Japan and the United States during World War II, in June, the government formally announced Tuesday.

The visit will be the first by any member of the Imperial family in the postwar era to any of the Pacific islands Japan once occupied. According to the Imperial Household Agency, this will be the first time an emperor has made an overseas trip for the sole purpose of paying homage to the souls of the war dead.

The Imperial Couple will leave Tokyo on June 27 and return home from the U.S. territory the following day, they said.