The defense ministers of Japan and South Korea on Sunday agreed to accelerate talks on ways to prevent radar lock-on incidents between their forces, despite remaining apart on an alleged case in 2018 that has undermined confidence between bilateral defense authorities.

Pledging to further promote defense cooperation, Japanese Defense Minister Yasukazu Hamada and his South Korean counterpart, Lee Jong Sup, apparently prioritized improving their ties amid the threat posed by North Korea's missile and nuclear development programs.

"Based on the outcomes of the talks this time, we will keep close communication with the South Korean side," Hamada told reporters after their meeting in Singapore, where they have been attending the three-day Asia Security Summit from Friday, also known as the Shangri-La Dialogue.

Japanese Defense Minister Yasukazu Hamada (R) and his South Korean counterpart Lee Jong Sup shake hands before their talks in Singapore on June 4, 2023. (Kyodo)

It was the first bilateral defense ministerial talks between Japan and South Korea in over three years.

Japan claims a South Korean navy destroyer directed its fire-control radar onto a Self-Defense Forces patrol plane in Japan's exclusive economic zone in the Sea of Japan in December 2018.

Seoul has denied the allegation, arguing that the destroyer was merely using radar to search for a drifting North Korean fishing boat, and the Japanese plane flew at low altitude near the warship.

Hamada said he conveyed to Lee Tokyo's position on the issue, but a Japanese Defense Ministry official told reporters that the differences between the two sides remained unsettled.

The two countries will discuss specific preventive measures at the working level in the future and bring up the incident when deemed necessary, the ministry said.

To cope with the "severe regional security environment and global issues," the ministers affirmed that the two nations will advance bilateral, as well as trilateral cooperation with the United States, their common security ally, the ministry said in a statement.

Japan and South Korea aim to enhance confidence between their defense authorities, including the defense ministers, and promote further exchanges at various levels, the ministry said.

Bilateral ties have been rapidly improving since South Korean President Yoon Suk Yeol proposed a solution to a longtime dispute over wartime labor compensation in March. Relations had sunk to their lowest point in decades under Yoon's predecessor, Moon Jae In.

Yoon visited Tokyo later that month and hosted Japanese Prime Minister Fumio Kishida in Seoul last month, resuming reciprocal visits by Japanese and South Korean leaders that had been halted since December 2011.

Last week, an SDF ship flying the rising sun flag, which Moon's administration called a symbol of Japan's wartime militarism, entered South Korea to join an international naval drill, suggesting that Seoul no longer regards the flag as problematic.

With North Korea repeatedly test-firing ballistic missiles since last year, Yoon, who took office in May 2022, has focused on the importance of trilateral defense cooperation with Tokyo and Washington.

Hamada and Lee strongly condemned the North's attempted launch of a spy satellite on Wednesday, saying it used ballistic missile technology in violation of U.N. Security Council resolutions aimed at curbing Pyongyang's nuclear and missile programs.

On Saturday in Singapore, Hamada and Lee attended a trilateral meeting with their U.S. counterpart Lloyd Austin, agreeing to launch a system to enable the three countries' real-time sharing of information about North Korean missiles by the end of this year.

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