TOKYO — Japanese Prime Minister Fumio Kishida was just 6 years old in 1963 when he and his family moved from Tokyo to New York, an entire hemisphere and endless cultural differences away.

The boy from ethnically homogenous Japan was struck by the diversity and generosity of his classmates while attending public school in Queens for three years, an impression that Kishida still recalls fondly six decades later.

Kishida can expect the same warmth during a state visit this week when he returns to the United States not just as the prime minister of his country, but as the one who has led the U.S.-Japan alliance to its strongest point.

“The world is now facing a historical turning point with Russia’s invasion of Ukraine, the Israeli-Palestinian conflict in the Middle East, and the security environment in East Asia,” he said in a one-on-one interview with The Washington Post at his official residence in Tokyo ahead of the visit. “It is important to demonstrate to the world the importance of the Japan-U.S. alliance and how strong it is in today’s uncertain international society.”

President Biden will host Kishida at the White House on Wednesday for a state dinner. On Thursday, Kishida is scheduled to deliver a speech at a joint meeting of Congress. Both will be the first for a Japanese prime minister in nine years.

The trip will underscore the two countries’ growing partnership, bound by concerns of an increasingly tumultuous security environment in East Asia. The two leaders are expected to discuss new areas of cooperation, including closer coordination between the U.S. forces in Japan and the Japanese military, and joint development and production of military and defense equipment.

Beyond security, the leaders plan to talk about cooperation in space, artificial intelligence, global supply chains and more. Kishida also will tour new Toyota and Honda plants in North Carolina to highlight Japan’s economic importance as the largest foreign investor in the United States.

“During the visit, I would also like to emphasize that the Japan-U.S. alliance is not a relationship that is formed solely between the leaders of the two countries, but also between the Congress, between governments, and many private companies, local governments, and so on,” Kishida said.

That emphasis is sure to revive controversy over Japanese company Nippon Steel’s planned acquisition of U.S. Steel, which has sparked an outcry from lawmakers from both parties and from the powerful United Steelworkers union.

The Japanese steelmaker has pledged not to cut jobs, but the deal nonetheless has become a flash point in Pennsylvania, a critical swing state where U.S. Steel is headquartered. Kishida said he does not plan to discuss the deal with Biden.

Other points of friction are likely to include the impasse in Congress over the $60 billion U.S. aid package for Ukraine, which has frustrated American allies, and Japan’s need to strengthen its cybersecurity capabilities, which U.S. officials think is a weak link in the alliance. And officials from both countries will look to lock in plans in case of an unpredictable U.S. president’s return.

Japan is now at the center of U.S. strategy to counter China through what American officials call a “latticework” of groupings between like-minded nations.

The latest step in cementing this strategy will be the first trilateral summit on Thursday between Biden, Kishida and Philippine President Ferdinand Marcos Jr. As China ramps up aggression in the South China Sea, rising maritime tensions have prompted Manila to draw closer to Tokyo and Washington. The three leaders are expected to announce new measures, including in maritime and economic security.

But this week’s pomp will mainly celebrate Kishida and the dramatic shifts Tokyo has made under his leadership to shed longtime postwar pacifist constraints.

In the past two years, Japan has taken previously unthinkable steps to bolster its defense capabilities, including increasing its defense budget to 2 percent of gross domestic product over five years, making it the third-largest in the world, and acquiring “counterstrike” capabilities to hit enemy bases with long-range missiles.

These moves demonstrate Japan’s growing desire to defend itself and better help enforce the global order. Since the Russian invasion of Ukraine, Kishida has repeatedly warned that “Ukraine today may be East Asia tomorrow.” The invasion triggered deep alarm in Japan that without a strong response, it could embolden China to attack Taiwan and lead to war in the Asia-Pacific region.

If Russia prevails, “it would show that force can actually bring benefits, even when breaking international law. If so, what would happen to East Asia? We must not allow any country to receive the wrong message,” Kishida said.

The prime minister recalled his visit in 2023 to Kyiv, where he spoke with victims in Bucha, the site of a civilian massacre by Russian troops, and said he was “outraged by the cruelty.”

“My visits to Kyiv and Bucha last March had a very significant impact on me,” Kishida said. “Actually touching the harsh and tragic reality of the war through the visit made me more determined in pursuing … lasting peace in Ukraine as soon as possible.”

The man who has led Japan through these dramatic changes is anything but dramatic. The mild-mannered leader almost never strays from prewritten talking points and has followed a traditional political career.

As a child living in Tokyo, Kishida spent every summer in Hiroshima, his family’s hometown. He would listen to stories from his grandmother and other survivors about the unfathomable horrors of nuclear devastation.

Kishida, 66, considers Barack Obama’s 2016 visit to Hiroshima, the first by a sitting U.S. president that he helped broker as foreign minister, among his most memorable achievements. Now, Kishida has hosted Group of Seven world leaders there twice, drawing attention to his oft-stated dream of a “world without nuclear weapons.”

“Many leaders understand this [need for nuclear disarmament] in their heads, but to be able to take serious and concrete action, I think it is important for them to actually see the tragic and harsh reality with their own eyes and feel it in their hearts themselves,” he said.

Kishida’s familial path into politics is a common one in Japan; he followed in the footsteps of his father and grandfather, who were both lawmakers.

He cut his teeth helping with his father’s election campaigns. Although he has had by far the highest title in three generations of Kishida men in politics, he credits his father with teaching him the fundamental values of public service.

After his father died in 1992, Kishida won his seat in Hiroshima, moving up the ranks before becoming prime minister in October 2021.

Diplomacy has been one of the few bright points of Kishida’s tenure that has been unscathed by scandals. Domestically, Kishida’s ruling Liberal Democratic Party has been mired in problems, including a massive political fundraising scandal that threatens his future as prime minister. Support for Kishida and his cabinet has been historically low.

Former Japanese prime minister Shinzo Abe laid the groundwork for Japan’s assertive foreign and defense policy, in hopes that Japan would play a bigger role on the global stage. But it is Kishida who put that plan into action, partly because he is not as divisive as Abe, many analysts say.

“He’s picked up on some of the important elements of the Abe revolution and advanced them in subtle and effective ways. He’s been able to do what Abe wasn’t able to do,” said Daniel Russel, former assistant secretary of state for East Asian and Pacific Affairs. “He’s got dovish politics and aura, but what that really means is that he’s trusted in ways that Abe never was. … That’s a huge asset, and he’s utilized it with real agility.”

One of the most dramatic moments of his term so far was the July 2022 assassination of Abe, Japan’s longest-serving prime minister. A year later, a man tried to attack Kishida. Both times, the politicians were on the campaign trail. And both times, Kishida insisted on immediately resuming campaign activities, saying the democratic process would not be deterred by violent attacks.

One area that U.S. officials are likely to laud during the visit is Kishida’s work with South Korean President Yoon Suk Yeol to break a 12-year diplomatic stalemate and work together to cooperate with Washington to counter threats in the region. Yoon’s overtures have led to a resumption of “shuttle diplomacy” as both men try to show they are serious about setting aside thorny historical issues from Japan’s colonization of Korea in the first half of the 20th century.

Historical issues have bedeviled the two countries’ periods of rapprochement. It could happen again, with changes in domestic politics in both countries. In fact, the Kishida-Biden summit will be on the same day as the National Assembly elections in South Korea, which could render Yoon a lame duck well before his term ends in 2027.

But Kishida said he learned as foreign minister that personal relationships make a huge difference in diplomacy, and that he hopes his relationship with Yoon will help the two countries build trust over time. The two men met seven times last year and have reportedly connected over their love for baseball and mutually high alcohol tolerance. Yoon has “never wavered in his promises or decisions, at least in my experience,” he said.

“Ultimately, it comes down to the relationship between the top officials who make the decisions on diplomacy,” Kishida said.

Julia Mio Inuma contributed to this report.