Japan and the United States held a joint ceremony Saturday on the island of Iwojima, now called Iwoto, to commemorate the 29,000 people who died in one of the fiercest battles of World War II.

The 16th observance of the now annual ritual, begun in 1985, was attended by veterans, kin of the dead and senior government officials from both sides, including welfare minister Yasuhisa Shiozaki and Defense Minister Gen Nakatani, the first Cabinet members to participate.

The event drew 550 people, about double last year's figure, as the nations prepare to mark the 70th anniversary of the end of the war.

Tetsuro Teramoto, who leads a group representing Japanese who lost relatives in the battle, thanked Japan and the U.S. for organizing the event and "transcending feelings of love and hatred."

Former Lt. Gen. Lawrence Snowden, who fought with the marines, said the event signaled the unity of the two countries.

The Battle of Iwojima lasted about a month after U.S. forces landed in February 1945. About 22,000 Japanese soldiers and 7,000 U.S. servicemen, mostly marines, died in the battle.

The remains of some 12,000 Japanese have not yet been recovered. The U.S. returned Iwoto to Japanese sovereignty in 1968.

At a Maritime Self-Defense Force facility on the island, Nakatani held talks with U.S. Navy Secretary Ray Mabus and agreed to deepen the alliance by revising the U.S.-Japan defense cooperation guidelines, officials said.

The guidelines detail the roles to be played by U.S. forces and the SDF in contingencies under the bilateral security treaty.