In a surprise announcement Monday night, Prime Minister Shinzo Abe said he would make a historic visit to Pearl Harbor with U.S. President Barack Obama — the first by a sitting Japanese leader to visit the place with the U.S. leader — on Dec. 26 and 27 during a trip for his final summit with him.

The stunning declaration came just two days ahead of the 75th anniversary of the attack that propelled the U.S. into World War II.

Abe said he was making the visit to Hawaii “to pay tribute” to military personnel from both sides of the Pacific who died in the war.

“We must never repeat the tragedy of the war,” he told reporters. “I would like to send this commitment. At the same time, I would like to send a message of reconciliation between Japan and the U.S.”

Abe said he agreed with Obama to visit Pearl Harbor together when he held brief talks with him on the sidelines of the Asia-Pacific Economic Cooperation forum in Lima last month.

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The Japanese leader said his last summit meeting with Obama will be a chance to reflect on his presidency and to confirm the importance of the bilateral relationship.

The Associated Press reported that the White House confirmed a meeting in Hawaii on Dec. 27, saying “the two leaders’ visit will showcase the power of reconciliation that has turned former adversaries into the closest of allies, united by common interests and shared values.”

In a historic and emotional visit to Hiroshima in May — the first by a sitting U.S. president — Obama paid a moving tribute to atomic bombing victims, reaffirmed the U.S.-Japan security alliance and friendship between both nations and called for the elimination of nuclear weapons.

Obama did not, however, include an apology for the dropping of the atomic bomb in August 1945, which some in both Japan and abroad had sought.

In May, the Nikkei newspaper reported that Abe was considering a visit to Pearl Harbor in November in a symbolic gesture to cement the alliance.

At the time, Chief Cabinet Secretary Yoshihide Suga said the government was not considering such a trip, but he added: “I don’t know about the future.”

The Nikkei report, an apparent government leak, may have been a trial balloon floated by Abe to gauge domestic and U.S. reactions.

The White House had said it would welcome such a visit, but speaking at a joint news conference with Obama ahead of the Group of Seven summit in Ise-Shima, Mie Prefecture, in May, Abe said there were no plans at that point.

The planned visit comes after Abe’s wife, Akie, made a surprise visit in August to Pearl Harbor, where she visited the USS Arizona Memorial, outside Honolulu. Her two-hour visit included offering prayers and laying flowers.

More than 2,400 U.S. servicemen and civilians were killed in the devastating sneak attack on Dec. 7, 1941 — a date that President Franklin D. Roosevelt said would “live in infamy.”

Once sworn enemies, the two nations became staunch allies after the war, with the U.S. currently stationing approximately 50,000 U.S. military personnel in Japan.

But the victory last month of Donald Trump in the U.S. presidential election has raised doubts about the alliance’s durability. Trump has said that allies such as Japan must cough up more cash for basing troops there or risk seeing them withdrawn.

Hoping to gauge Trump’s commitment to the alliance, Abe was the first world leader to meet the president-elect when he visited New York last month. He did not disclose details of the talks, but said that Trump is a leader he can have great confidence in.