TOKYO -- Japanese officials on Tuesday dismissed the idea of scrapping restrictions on semiconductor materials exports to South Korea, saying the controls are a matter of national security and are not up for negotiations.

"The latest step has been taken to improve the implementation of the export control regime," Japanese Trade Minister Hiroshige Seko said during a regular news conference. "It is not subject to negotiations [with South Korea], and it cannot be just withdrawn."

Seko also reiterated the government's position that the policy does not breach World Trade Organization rules, and dismissed South Korea's suggestion that it could haul Japan before the international trade body.

He said Japan is willing to explain the new policy to South Korea, acknowledging that Seoul has asked for more information.

Japan on Thursday introduced new rules requiring its exporters of semiconductor materials to seek government approval before they ship to South Korea, a move that could disrupt chip production there.

Chief Cabinet Secretary Yoshihide Suga, the top government spokesman, also said Japan will stand firm, after South Korean President Moon Jae-in demanded on Monday that the restrictions be withdrawn and a sincere discussion be held between the two countries.

Suga, too, argued the policy is not subject to negotiations with other governments and cannot be simply withdrawn.