Japanese Prime Minister Shinzo Abe presents a wreath at the National Memorial Cemetery of the Pacific at Punchbowl in Hono­lulu on Dec. 26, 2016. (Hugh Gentry/Reuters)

Japanese Prime Minister Shinzo Abe’s historic visit to Pearl Harbor with President Obama on Tuesday punctuates the Obama administration’s multiyear effort to prod Japan and its neighbors in Asia to decrease tensions by moving beyond lingering wartime grievances.

But as the two leaders pay homage to the 2,403 Americans who died in the surprise Japanese attack on Dec. 7, 1941, the geopolitical backdrop for the event has been clouded by President-elect Donald Trump’s pugnacious and unpredictable foreign-policy pronouncements. During the campaign, Trump raised alarms in both countries when he questioned the value of the U.S. military’s basing agreements in Japan and suggested the island nation consider developing its own nuclear weapons.

Abe is set to become the first Japanese leader to take part in a ceremony at the USS Arizona Memorial, which honors the American sailors and Marines who perished aboard the battleship 75 years ago. The trip, in the works before Trump’s election last month, is intended as a symbolic bookend to Obama’s visit in May to Hiroshima, where the United States deployed the world’s first atomic bomb.

Like Obama, Abe does not plan to apologize for Japan’s sneak attack, which wounded an additional 1,178 and prompted the United States’ entry into World War II. Rather, he will reflect on history “and renew the determination of the Japanese people not to repeat the devastation of war,” said Tamaki Tsukada, spokesman for the Japanese Embassy in Washington.

U.S. military veterans are expected to take part in a ceremony that will be “a powerful demonstration of how the two countries can overcome a very painful history to become the closest of allies and friends,” Daniel Kritenbrink, the White House’s senior director for Asian affairs at the National Security Council, told reporters.

The USS Arizona Memorial, marking the resting place of the crewmen killed on December 7, 1941 when Japanese Naval Forces bombed Pearl Harbor, is pictured on December 24, 2016. (Jerome Cartillier/AFP/Getty Images)

Abe’s visit marks another delicate step toward broader regional reconciliation in Asia, though it is unlikely to satisfy demands in South Korea and China that the Japanese government formally apologize and atone for wartime atrocities. Three of Abe’s predecessors, including his grandfather, Nobusuke Kishi, a former prime minister, purportedly visited Pearl Harbor in the 1950s, but none took part in a ceremony to pay homage to the dead over concerns about right-wing political opposition in Japan.

[Is Abe the first sitting Japanese leader to visit Pearl Harbor? Well, actually, he may be the fourth.]

Such a visit seemed unlikely as recently as three years ago, when Abe, leader of the conservative Liberal Democratic Party, visited Tokyo’s Yasukuni Shrine, the paean to Japan’s wartime dead, in a move that inflamed regional tensions and irritated the White House. The Obama administration has sought to improve relations in Asia, especially between U.S. allies Japan and South Korea, to hedge against China’s rise and address shared challenges, such as a nuclear-armed North Korea.

Since then, Tokyo has negotiated, with support from the White House, a resolution with Seoul over the forced use of women as sex slaves by Japan’s imperial army. And Abe expressed remorse for the war during remarks to a joint meeting of the U.S. Congress last year ahead of the 70th anniversary of the end of World War II.

Obama’s speech in Hiroshima, where he warned of the danger of nuclear weapons and urged disarmament, was well received in Japan, prompting Abe to pursue the reciprocal visit to Pearl Harbor. Obama is in Hawaii for his annual two-week winter vacation.

Their visit “is a demonstration about how far the world has come in many instances,” said Hawaii Gov. David Ige (D), the son of a World War II veteran who in 2014 became the state’s second governor of Japanese ancestry.

About one-sixth of Hawaii’s population is of Japanese ancestry, and Japan sent 1.5 million tourists to the state last year, more than any other country. Abe, who arrived in Oahu on Monday, opened his visit with a wreath-laying ceremony at the National Memorial Cemetery of the Pacific, a military cemetery known as Punchbowl.

The prime minister is scheduled to have a formal bilateral meeting with Obama before visiting the USS Arizona Memorial.

Ige said the relationship between the Japanese people and Hawaii “is more than business, more than friendship — it’s family.” He called the U.S.-Japan military alliance “the most important to keeping the peace in Asia.”

The question is what becomes of that alliance under Trump.

Along with questioning U.S. basing agreements in Japan and South Korea, Trump suggested in March that the two U.S. allies are freeloading off the United States’ security umbrella. His suggestion that they consider developing their own nuclear weapons drew sharp rebukes from the Obama White House, which called the idea “catastrophic,” and national security experts in both political parties.

Trump also has vowed to rip up the 12-nation Trans-Pacific Partnership trade deal negotiated by the Obama administration that includes Japan. Abe expended significant political capital to move the accord through the Japanese parliament over objections from protectionist domestic rice and automobile industries.

Within days of Trump’s election, Abe rushed to begin building ties, becoming the first foreign leader to meet with the president-elect during a stopover in New York in November en route to an Asia-Pacific economic summit in Peru.

“Trump’s campaign rhetoric is campaign rhetoric,” said Tsukada, the embassy spokesman. “We don’t believe the electorate or constituents take those message literally. In fact, you might have noticed that throughout the campaign, at one stage his rhetoric was extremely anti-Japan, with Japan-bashing type of language, but after a certain point it disappeared. By and large, we think he has a normal kind of balance.”

Some foreign-policy analysts have speculated that Abe will seek to leverage the uncertainty around Trump’s agenda to speed his own long-standing efforts to bolster the mission and capabilities of Japan’s Self-Defense Forces. Abe played host this month to Russian President Vladi­mir Putin, who visited the prime minister’s home town, in a bid to improve bilateral relations between their countries. That meeting, which had been in the works before Trump’s victory, caused consternation in Washington.

Trump’s antagonistic posture toward China, including his unprecedented phone conversation with the president of Taiwan this month, also has unsettled the region. Analysts said Abe would welcome a shift of U.S. policy toward Taiwan, but they cautioned that China’s response to an escalation of tensions with the Trump administration could be aimed at Japan, as well.

Tokyo is “relatively reassured that [Trump’s] campaign rhetoric of extreme isolationism is gone, but the unpredictability factor is still the biggest challenge,” said Sheila Smith, a Japan expert at the Council on Foreign Relations. “What Abe will want to do with Trump is to hug him close, and teach him about Japan and Asia.

“I suspect they’re holding their breath a little bit,” Smith added. “But I do think in Mr. Abe’s personal visit and his subsequent follow-up, he’s trying to be the ally of choice for Mr. Trump.”

Lyte reported from Hono­lulu.