Japan protested Wednesday what it sees as inaction by the South Korean government to prevent Japanese corporate assets from being sold as part of a wartime labor dispute.

The protest came after a team of lawyers for South Koreans who were awarded damages from Japanese steelmaker Nippon Steel Corp. and machinery manufacturer Nachi-Fujikoshi Corp. over wartime labor said earlier in the day they had asked a court to sell assets seized from the firms in South Korea.

Kenji Kanasugi, director-general of the Japanese Foreign Ministry’s Asian and Oceanian Affairs Bureau, called a senior South Korean Embassy official in Tokyo to lodge the protest.

Kanasugi said Seoul has yet to take concrete steps to correct the violations of a 1965 bilateral accord that settled wartime compensation issues.

Kanasugi also reiterated Japan’s demand for bilateral talks on the matter.

The plaintiffs’ action is extremely regrettable, Chief Cabinet Secretary Yoshihide Suga said on television.

Nippon Steel and Nachi-Fujikoshi each have assets in South Korea in the form of stakes in companies. Some of their stakes were seized by South Korean courts in January and March, respectively, after both refused to compensate the plaintiffs after courts ruled against them.

The lawyers in a statement accused the Japanese government of pressuring the firms to take no action about the compensation, and alleged that such inaction contravenes international law.

The latest move will likely further aggravate ties between the two countries, as the Japanese government has hinted that it may retaliate if the interests of Japanese businesses are hurt over the dispute.

Tokyo claims that the issue of compensation arising from its 1910-1945 colonization of the Korean Peninsula was settled under a bilateral agreement signed when the two countries established diplomatic ties in 1965.

But South Korea’s Supreme Court ruled on Oct. 30 that the right of victims of what it called “forced mobilization” during World War II to seek compensation was not terminated by the agreement.

In the same ruling, the top court ordered Nippon Steel, then known as Nippon Steel & Sumitomo Metal Corp., to pay plaintiffs a total of 400 million won (about $343,000) in compensation.

Subsequently, the plaintiffs successfully sought the seizure of about 81,000 shares Nippon Steel has in Posco-Nippon Steel RHF Joint Venture Co., a joint venture with South Korean steelmaker Posco that is known simply as PNR.

Nachi-Fujikoshi’s cases are still pending at the Supreme Court. Lower courts, earlier, ruled against the company. A court has seized the company’s stake in an affiliated company in South Korea estimated to be worth 765 million won.

Besides the two Japanese companies, manufacturer Mitsubishi Heavy Industries Ltd. has had its rights to two trademarks and six patents in South Korea seized over wartime labor.

Wednesday’s statement showed that the lawyers have asked Seoul Central District Court to request the Japanese manufacturer to specify all its South Korean assets apart from the ones that have already been seized.

The lawyers indicated that the sales would take at least three months to complete, and that they could be stopped if the companies agree to compensation talks.

Wednesday’s move comes just days after more South Koreans who claim they or their family members were forced to work for Japanese companies during the war sued nine Japanese firms, including Mitsubishi Materials Corp., Nishimatsu Construction Co. and Hitachi Zosen Corp., as well as the three companies.