The film marks Eastwood's second collaboration with Spielberg

Eastwood will direct an adaptation of best-selling book Flags of Our Fathers: Heroes of Iwo Jima later this year.

He told Governor Shintaro Ishihara that he would "absolutely not" trample on Japanese feelings.

The battle for the island of Iwo Jima, in 1945, left 21,000 Japanese and 6,800 US soldiers dead in a single month.

The World War II battle was a turning point in the fight for control of the Pacific.

Many of the Japanese soldiers who died on the island, 1,200 kilometres south of Tokyo, remain unaccounted for more than half a century later.

The Iwo Jima Memorial in Virginia commemorates the battle

Relatives of fallen Japanese soldiers have opposed any building on the island which they consider to be hallowed ground.

The director hopes to begin filming on the island later this year, but has yet to ask Tokyo's permission, metropolitan government spokesman Katsumi Kumagai said.

The battle of Iwo Jima produced one of the war's most enduring images - a photograph of six US marines raising a flag on the flank of Mount Suribachi, the island's highest point.

Flags of Our Fathers is the second collaboration between Eastwood and Steven Spielberg, following The Bridges of Madison County in 1995.