SEOUL, Sept. 11 (Xinhua) -- South Korea on Wednesday filed a complaint with the World Trade Organization (WTO) against Japan over its restrictions on the export to South Korea of three materials vital to make memory chips and display panels.

Trade Minister Yoo Myung-hee told a press briefing that the South Korean government decided to file the suit with the WTO over Japan's moves in order to protect national interests and prevent the repeated abuse of trade for the political purpose.

Yoo said Japan's export curbs were a discriminatory act directly targeting South Korea and were politically motivated against the South Korean top court's rulings on the wartime forced labor, just as the Japanese figures in the cabinet member level repeatedly mentioned.

The WTO filing came after Japan tightened regulations on July 4 over its export to South Korea of the three materials crucial for the production of memory chips and display panels, the mainstay of the South Korean export.

Japan's export restrictions came in an apparent protest against the South Korean top court's rulings ordering some of Japanese companies, including Nippon Steel and Mitsubishi Heavy Industries among others, to compensate the South Korean victims who were forced into hard labor without pay by Imperial Japan. The Korean Peninsula was colonized by Japan from 1910 to 1945.

Japan claimed that all the colonial-era issues were settled via the 1965 treaty, which normalized diplomatic relations between Seoul and Tokyo, but South Korea said the treaty did not involve individuals' right to damage compensation.

Yoo noted that South Korea would listen to Japan's position through bilateral consultations while pointing out the illegality and unfairness of Japan's moves, saying that if not settled through the bilateral consultations, Seoul would actively take on the dispute settlement process.

With the WTO filing, South Korea and Japan would be required to hold talks for the settlement over the next two months. If the two sides fail to narrow differences, the WTO Dispute Settlement Body would set up a panel to reach a conclusion. The final ruling was expected to take two to three years.

Japan removed South Korea in August from its whitelist of trusted trading partners that are given preferential export procedure, but Seoul excluded the removal from its filing with the WTO this time.

The trade minister said South Korea was reviewing how to react to the whitelist removal with all possibilities being open. In response to Japan's moves, Seoul also dropped Tokyo off its whitelist of trusted export partners last month.