The government on Friday criticized South Korea's decision to ask the World Trade Organization (WTO) to set up a dispute settlement panel over Japan's tightening of export controls on semiconductor materials.
Trade minister Hiroshi Kajiyama called the move "extremely regrettable," saying the issue should be resolved through bilateral discussions.
"This unilateral move by South Korea could be a breach of our agreement to work toward a resolution through dialogue and communication," he said at a news conference.
South Korea sent a formal request on Thursday asking the WTO Secretariat in Geneva to appoint a panel of experts to consider the case.
Foreign Minister Toshimitsu Motegi said Tokyo had relayed its concerns to Seoul over the move, without elaborating.
In July last year, Japan imposed tougher restrictions on South Korea-bound exports of three materials used to manufacture semiconductors and display panels. The following month, it removed its neighbor from a "white list" of trusted trade partners, citing concerns over Seoul's lax rules on exporting sensitive goods.
South Korea argues Japan's measures are retaliation for a diplomatic dispute over wartime labor compensation, and violate WTO rules. It originally filed the claim last September, but suspended it in November after the countries agreed to start bilateral consultations.
Seoul has accused Japan of not holding up its end of the deal to ease export controls, despite the South Korean side having addressed Tokyo's concerns, saying earlier this month that it would resurrect the WTO case.
Ties between the Asian neighbors have been on particularly rocky ground since South Korea's top court made a series of decisions ordering compensation for people ruled to have been forced to work in Japanese factories during the 1910-45 period of Japan's colonial rule of the Korean Peninsula.