South Korea has formally asked the International Olympic Committee to ban the Japanese "rising sun" flag at next year's Tokyo Games, calling it a symbol of Japan's brutal wartime past and comparing it with the Nazi swastika.
Japan imposed export controls in early July targeting three essential chemicals used in products produced by South Korean tech giants such as Samsung and LG.
Japan said that Japanese valves are mainly used in equipment for semiconductor manufacturing and automotive engine production where high-level precision is crucial, and do not directly compete with Korean valves, which are low-end products commonly used in things like equipment for painting cars.
Tokyo said the move was due to a "loss of trust" in relations with Seoul, but also accused South Korea of improperly handling exports of sensitive materials from Japan.
Japan insists that all compensation matters were settled when the two countries normalized relations under a 1965 treaty and that the South Korean court rulings go against global law.
In addition, Japan has changed export procedures for three materials that were traded freely with an general permit so that now they require individual permits.
She said Japan has violated the WTO's obligation to not discriminate. Yoo said Japan approved the shipments of the materials only three times since the measures took effect on July 4.
"Seoul's complaint will not lead Japan to drop its tighter export curbs on the three items, but this will certainly put pressure on Japan to cautiously implement the measures", said Ahn Duk-geun, a professor at Seoul National University.
The Geneva-based organization's appellate body, the top entity in its dispute settlement process, said South Korea is in violation of its rules after imposing duties of 11.66 to 22.77 percent on Japan-made pneumatic valves from August 2015. South Korea is taking steps to drop Japan from its own white list.
The flag, portraying a red sun with 16 rays extending outward, is resented by many South Koreans, who still harbor animosity over Japan's 1910-1945 colonial rule of the Korean Peninsula.
If the two sides fail to reach an agreement within 60 days of commencing talks, Seoul plans to take the case to a WTO panel that arbitrates trade disputes.