Japan warned Thursday of "serious" ramifications if a South Korean court ruling against Mitsubishi Heavy Industries Ltd. related to wartime labor is enforced.

The court has ruled that payments worth around 850 million South Korean won (¥80 million) owed by South Korean companies to Mitsubishi Heavy could be seized and used to compensate victims of forced labor during Japan's colonial rule.

A team of lawyers representing South Koreans said late Wednesday that the Suwon District Court had approved on Aug. 12 the legal move concerning the 850 million won.

"If it's liquidated, that would push Japan-South Korea relations into a serious situation. It must be avoided," Chief Cabinet Secretary Katsunobu Kato told reporters in Tokyo on Thursday. "We want to urge South Korea even more strongly to present a solution that is acceptable to Japan."

A Mitsubishi Heavy spokesperson declined to comment, saying the company was trying to confirm details on the ruling.

In 2018, South Korea's Supreme Court ordered Mitsubishi Heavy to compensate former forced workers from South Korea, setting a precedent and drawing a strong rebuke from Japan, which argues that the matter was settled under a 1965 treaty.

The ruling against Mitsubishi Heavy and a similar top court ruling against Nippon Steel Corp. in October 2018, as well as subsequent legal moves, have strained bilateral ties.

Kato reiterated Tokyo's stance that issues relating to property and claims stemming from Japan's colonial rule of the Korean Peninsula from 1910-45 were resolved in the 1965 bilateral agreement.