South Korea on Wednesday officially dropped Japan from its "white list" of trusted tre partners, latest move in a bitter row stemming from Tokyo's use of forced labour during World War II. South Korea h alrey warned Tokyo it would reciprocate following a similar move by Japan in late August to downgre South Korea's tre status. Local companies shipping strategic goods to Japan would w have to submit more documents and approval would take around 15 days inste of five, Yonhap news ncy reported, quoting South Korean tre ministry. Seoul and Tokyo have been embroiled in tre dispute since July, when Japan tightened export controls on three chemicals essential to key products of South Korean tech companies such as Samsung.

RE | rth Korea test-fires 'Super Large Multiple Rocket Launcher'

South Koreans boycott Japanese goods

Tokyo says its decision was me on grounds of national security, but it followed a series of South Korean court rulings ordering Japanese firms to pay for forced labour during World War II. South Koreans have since mounted a widespre boycott of Japanese goods, including beer, cosmetic products and cars, among ors. Imports of Japanese beer -- long a firm favourite with South Korean drinkers -- slumped to almost zero last month, according to tre data released Monday. Several South Korean airlines including flag carrier Korean Air have also suspended routes to Japan because of falling demand from South Koreans.

RE | South Korea on highest alert after African swine fever found

Japanese firms see slump

Japanese automakers have also seen sales in South Korea slump in recent months. Both Japan and South Korea are market ecomies and y are major US allies faced with an overbearing China and nuclear-armed rth Korea. But ir relationship continues to be heavily affected by Japan's 35-year-old colonial rule of Korean peninsula in early 20th century. Japan says all reparations claims were settled under a 1965 treaty and associated ecomic agreement that was supposed to have rmalised ir relations.

RE | Kim Jong Un invited Donald Trump to rth Korea in new letter: Report