South Korea's President Moon Jae-in has urged Japan to withdraw export controls on high-tech materials bound for South Korea as a row over forced wartime labor threatened to disrupt global supplies of South Korean memory chips and smartphones.

In his first public remarks on Japan's restriction on exports to South Korea, Moon said that a "vicious cycle" of action by the uneasy neighbors was something both of them should avoid.

South Korea's tech giant Samsung Electronics Co and SK Hynix Inc - the world's top memory chipmakers, and suppliers to Apple and China's Huawei Technologies - could face delays if the Japanese measures, which took effect on Thursday, drag on.

Japan tightened restrictions on the export of the high-tech materials to South Korea in connection with a dispute over compensation for forced wartime labor.

The row between the two countries flared last October when South Korea's Supreme Court ruled that Japan's Nippon Steel must compensate South Koreans for forced labor during World War II. Japan maintains that the issue of forced labor was fully settled in 1965 when the two countries restored diplomatic ties, and has denounced the South Korean court ruling as "unthinkable."

Moon said South Korea could not rule out countermeasures if the Japanese action inflicted damage on South Korean companies, although he said he did not want to see that.