Chief Cabinet Secretary Yoshihide Suga has described South Korea's criticism of Japan's tighter screening of exports as groundless.
Japan has decided to remove South Korea from a list of countries entitled to simplified export procedures.
South Korean President Moon Jae-in has reacted sharply to Japan's move. He said South Korea won't sit back and allow an instigator to continue its aggressive posture.
Suga told reporters on Monday that he doesn't want to comment on every remark made by the countries' leaders.
Suga insisted that Japan has made a necessary review of its export controls from a national security standpoint.
South Korea's Fair Trade Commission has ordered four Japanese companies to pay a total of about 7.6 million dollars in fines.
Suga said he believes the companies will respond properly after closely examining the order.