SEOUL--South Korea's economic policy chief warned on Thursday of direct countermeasures against Japan if it keeps restrictions on exports of high-tech materials to its companies for a long time.

"Implementing corresponding measures against Japan cannot be ruled out because it will take a long time for the World Trade Organization to produce a conclusion," Finance Minister Hong Nam-ki said on radio.

Japan has said it would tighten curbs on exports of three materials used in smartphone displays and chips to South Korea amid a growing dispute over wartime forced labor. South Korea has so far sought to settle the issue through the WTO.

Hong also said he expected the South Korean central bank's monetary policy committee to take recent changes in economic conditions into account when it decides on its interest rate policy.