The government has found 83 new U.S. documents concerning the burial of remains of Japanese soldiers who died on Iwojima, one of the fiercest battlefields in the Pacific theater, government sources said Wednesday.

The Health, Labor and Welfare Ministry has confirmed the documents indicating the specific dates and locations of such burials by U.S. forces at the U.S. National Archives and Records Administration, leading to the possibility of more remains of Japanese soldiers being recovered on the volcanic island, now officially known as Iwoto.

Although about 21,900 Japanese soldiers died in the Battle of Iwojima, the remains of only 8,700 Japanese soldiers have been retrieved.

A government survey group will visit the island for about a week from Thursday to identify the burial places of Japanese soldiers before a mission tours the island to gather the remains from late September.

The group will include Yukihiko Akutsu, one of Prime Minister Naoto Kan's assistants, who heads a special government team to recover the remains of Japanese soldiers.

The government set up the special team as the prime minister vowed to retrieve the remains of all Japanese soldiers on Iwoto after Health, Labor and Welfare Minister Akira Nagatsuma visited the island in July.

SDF members will join the survey group, which will also include officials from the Defense Ministry and the welfare ministry.