The film marks Eastwood's second collaboration with Spielberg

Eastwood will direct an adaptation of James Bradley's book Flags of Our Fathers: Heroes of Iwo Jima for Spielberg's Dreamworks studio.

The battle for the island of Iwo Jima, in early 1945, was a turning point in the fight for control of the Pacific.

It left 21,000 Japanese and 6,800 US soldiers dead within a single month.

The battle 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.

Survivors

Of the six men in the photograph, three were killed in combat.

The Iwo Jima Memorial in Virginia commemorates the battle

Those who survived were hailed as heroes but one, Ira Hayes, took refuge in drink and died in a fight, while another, Rene Gagnon, could not convert his fame into a full-time job.

The last was John Bradley, who never spoke about his experiences to his family.

After his death in 1994 his son, James, found out about his father's heroism and wrote the best-selling book on which the film will be based.

The project is the second collaboration between Spielberg and Eastwood, following The Bridges of Madison County in 1995, which Eastwood directed and starred in, and Spielberg produced.

The script for Flags of Our Fathers is being written by Paul Haggis, who is also working with Eastwood on another film, with the working title Million Dollar Baby.