Japan’s prime minister expressed sympathy for the suffering of Korean forced laborers during Japan’s colonial rule, as he and his South Korean counterpart on Sunday renewed resolve to overcome historical grievances and strengthen cooperation in the face of shared challenges such as North Korea’s nuclear program.

Comments by Japanese Prime Minister Fumio Kishida during his second summit in less than two months with South Korean President Yoon Suk Yeol are closely watched in Seoul.

Yoon has faced domestic criticism that he had preemptively made concessions to Tokyo without getting corresponding steps in return. Kishida’s statement, which avoided a new, direct apology over the colonization but still sympathized with the Korean victims, suggests he felt pressure to say something to maintain momentum for improved ties.

“And personally, I have strong pain in my heart as I think of the extreme difficulty and sorrow that many people had to suffer under the severe environment in those days," Kishida told a joint news conference with Yoon, referring to Japan’s 1910-45 colonial rule of the Korean Peninsula.

“Japan and South Korea share various history and development, and I believe it is my responsibility as prime minister of Japan to cooperate with President Yoon and the South Korean side as we follow through the effort of our predecessors who have also overcome the difficult times," he said.

Kishida arrived in South Korea earlier Sunday for a two-day visit, which reciprocates a mid-March trip to Tokyo by Yoon and marks the first exchange of visits between the leaders of the Asian neighbors in 12 years.

The back-to-back summits were largely meant to resolve the countries' bitter disputes caused by the 2018 court rulings in South Korea that ordered two Japanese companies to financially compensate some of their aging former Korean employees for colonial-era forced labor. Japan has refused to abide by the verdicts, arguing that all compensation issues were already settled when the two countries normalized ties in 1965.

The wrangling led to the countries downgrading each other’s trade status and Seoul's previous liberal government threatening to spike a military intelligence-sharing pact. The strained South Korea-Japan ties complicated U.S. efforts to build a stronger regional alliance to better cope with rising Chinese influence and North Korean nuclear threats.

In March, however, Yoon’s conservative government took a major step toward mending the ties by announcing it would use local funds to compensate the forced labor victims without demanding contributions from Japanese companies. Later in March, Yoon traveled to Tokyo to meet with Kishida, and the two agreed to resume leadership-level visits and other talks. Their governments have since taken steps to withdraw their economic retaliatory steps against each other.

Yoon’s push, however, drew strong backlash from some of the forced labor victims and his liberal rivals at home, who have demanded direct compensation from the Japanese companies. Yoon has defended his move, saying greater cooperation with Japan is required to jointly tackle North Korea’s advancing nuclear program, the intensifying U.S.-China strategic rivalry and global supply chain challenges.

“We should stay away from a thinking that we must not make a step forward for our future cooperation because our history issues aren’t settled completely,” Yoon said Sunday.

Kishida reaffirmed his government upholds the positions of previous Japanese administrations, including the landmark 1998 joint declaration by Tokyo and Seoul on improving ties, but didn’t make a new apology. In that declaration, then-Japanese Prime Minister Keizo Obuchi said: “I feel acute remorse and offer an apology from my heart” over the colonial rule.

Japanese governments have expressed remorse or apologies over the colonial period numerous times. But some Japanese officials and politicians have occasionally made comments that have been accused of whitewashing Tokyo’s wartime aggressions, prompting Seoul to urge Tokyo to make new, more sincere apologies.

Ahead of his summit with Yoon, Kishida and his wife, Yuko Kishida, visited the national cemetery in Seoul, where they burned incense and paid a silent tribute before a memorial. Buried or honored in the cemetery are mostly Korean War dead, but include Korean independence fighters during the period of Japanese rule. Kishida was the first Japanese leader to visit the place in 12 years.

“Kishida’s comments about Koreans who suffered under Japanese colonialism may be criticized for not being more specific about historical perpetrators and more apologetic toward historical victims,” Leif-Eric Easley, a professor at Ewha University in Seoul, said. “But Kishida did visit South Korea’s national cemetery and said that his heartfelt views, respect for the past, and recognition of current global challenges produce a sense of responsibility for improving Seoul-Tokyo relations.”

Yoon said talks among Seoul, Tokyo and Washington are underway to implement their earlier agreement on sharing information on North Korean missile launches. Yoon said he and Kishida reaffirmed that North Korea’s nuclear and missile programs pose a grave threat to the two countries and the rest of the world.

In late April, Yoon made a state visit to the United States and agreed with President Joe Biden to reinforce deterrence capabilities against North Korea's nuclear threats. During a joint news conference, Biden thanked Yoon “for your political courage and personal commitment to diplomacy with Japan.”

Yoon, Biden and Kishida are expected to hold a trilateral meeting later this month on the sidelines of the Group of Seven meetings in Hiroshima to discuss North Korea, China's assertiveness and Russia's war on Ukraine. Yoon was invited as one of eight outreach nations.

Kishida said he and Yoon would pay respects before a memorial for Korean atomic bomb victims in Hiroshima.

Seoul and Tokyo have a slew of other sensitive historical and territorial disputes, mostly related to the Japanese colonization. In a reminder of the delicate nature of their ties, diplomats between the two countries last week spatted over a South Korean lawmaker’s visit to disputed islets located in the waters between the two countries. Earlier, Seoul protested Kishida’s offering of religious offerings to a Tokyo shrine that it views as a symbol of Japan’s wartime aggression.