The Japanese prime minister Shinzo Abe has offered condolences on behalf of his country during a historic pilgrimage to Pearl Harbor, scene of the attack that catapulted the US into World War Two.
Flanked by Barack Obama at the site in Hawaii, the pair placed wreaths made of lilies and flower petals into the water where USS Arizona was sunk 75 years ago.
The leaders also met survivors from the battle on 7 December 1941 when more than 350 Japanese aircraft attacked the US Naval Base in Hawaii killing around 2,300 US servicemen.
"As the prime minister of Japan, I offer my sincere and everlasting condolences to the souls of those who lost their lives here, as well as to the spirits of all the brave men and women whose lives were taken by a war that commenced in this very place," Abe said, adding: "We must never repeat the horrors of war again".
He did not apologise but his visit is seen as significant and comes six months after Obama became the first sitting US president to visit Hiroshima, where the US dropped an atomic bomb during WW2, killing an estimated 150,000 people.
Abe also visited the National Memorial Cemetery of the Pacific near central Honolulu and laid a wreath.
In what is thought to be his last meeting with a foreign leader as president, Obama said: "As we lay a wreath or toss flowers into waters that still weep, we think of the more than 2,400 American patriots, fathers and husbands, wives and daughters, manning heaven's rails for all eternity."
Daniel Kritenbrink, Obama's White House Asia adviser said, according to the Associated Press: "This visit, and the president's visit to Hiroshima earlier this year, would not have been possible eight years ago.
"That we are here today is the result of years of efforts at all levels of our government and societies, which has allowed us to jointly and directly deal with even the most sensitive aspects of our shared history," he said.