Overshadowed by the threats of a renewed nuclear arms race under incoming President Donald Trump, Japanese Prime Minister Shinzo Abe and U.S. President Barack Obama made a historic visit to Pearl Harbor on Tuesday in a symbolic show of unity and reconciliation.

Daniel Kritenbrink, Obama’s top Asia adviser in the White House, said the visit was part of an effort to “directly deal with even the most sensitive aspects of our shared history.”

Although Japanese leaders have visited Oahu’s Pearl Harbor before, “Abe will be the first to visit the memorial constructed on the hallowed waters above the sunken USS Arizona,” AP notes, where more than 2,300 Americans died during the Dec. 7, 1941 bombing, spurring U.S. engagement in World War II. 

Last spring, Obama became the first sitting U.S. president to visit Hiroshima, Japan, where U.S. forces dropped an atomic bomb, killing 140,000 people and effectively ending the war.

“Abe will not apologize for Pearl Harbor, his government has said. Nor did Obama apologize at Hiroshima in May,” AP noted, which many observers saw as a slight, given the United States’ vast nuclear weapons arsenal.

Despite the leaders’ unrepentance, national military organization Veterans for Peace issued a statement of atonement on Tuesday to the people of Japan “and to all the people of the world” for U.S.’ usage of nuclear weapons. 

“This hugely atrocious crime against humanity should never have happened,” the group stated. “As military veterans who have come to see the tragic futility of war, we promise that we will continue working for peace and disarmament.”