Nikkei staff writers

TOKYO — Japan, China and South Korea will postpone a planned trilateral summit until next year because of simmering tensions between Tokyo and Seoul over wartime labor, Nikkei has learned.

South Korea was supposed to host the meeting this year. But Seoul has not offered a specific schedule or agenda, and is now expected to seek a date early in 2021.

Japan maintains that Prime Minister Yoshihide Suga cannot visit South Korea unless Seoul offers some assurance that assets of Japanese companies will not be seized over their use of Korean workers during World War II.

A senior Japanese government official told Nikkei on condition of anonymity that “it is no longer possible to hold the summit this year.”

South Korean President Moon Jae-in sees the trilateral summit as a way to warm his country’s ties with Japan. But Suga has been reluctant to meet given recent developments over the wartime labor issue.

In 2018, the South Korean Supreme Court ordered Japanese companies to compensate Koreans who were forced to work in mines and factories during the war. Later, district courts ruled that the assets of Nippon Steel and Mitsubishi Heavy Industries were eligible for seizure to pay.

Japan maintains that a treaty with South Korea reached in 1965 “settled completely and finally” any such wartime claims.

South Korea sent officials to Japan in November, looking to ease the tensions. Intelligence chief Park Jie-won proposed the idea of a bilateral declaration to Suga. Kim Jin-pyo, who heads the South Korea-Japan Parliamentarians’ Union, urged Suga to visit the country by the end of the year.

Despite the delay, South Korea remains committed to hosting the summit, which it sees as a diplomatic achievement at a time of uncertainty over the Korean Peninsula owing to the U.S. presidential transition.

Moon also wants Japan’s cooperation in order to resume a dialogue with North Korea following the Tokyo Olympic and Paralympic games next summer

But setting a date could prove challenging, given the two court cases regarding wartime “comfort women” — another thorn in the bilateral relationship — expected to be ruled on early next year in South Korea. Seoul and Busan also face mayoral elections in April, while Japan is preparing for the Olympics in the summer as well as a parliamentary lower house election sometime before October.

November and December are usually busy months for diplomacy. In 2019, then-Japanese Prime Minister Shinzo Abe attended Association of Southeast Asian Nations summits in Bangkok in November, then the trilateral summit in China in late December.

But the coronavirus has forced many such international forums online this year. Japan and South Korea both face another wave of infections, with South Korea seeing over 500 new cases each day, making pandemic response at home a top priority.

This will be the first year in a decade in which Japan’s prime minister does not travel overseas in November or December.