Responding to criticism from a former U.S. ambassador to Japan, Chief Cabinet Secretary Yoshihide Suga told reporters Tuesday the administration is not considering revising a key apology to wartime sex slaves.

Former U.S. Ambassador Thomas Schieffer reportedly told a symposium Friday in Washington that revising the statement, issued by Chief Cabinet Secretary Yohei Kono in 1993, would gravely damage Japanese interests in both Asia and the U.S.

"I don't think I have ever said we are conducting a study that could include revision" of the Kono statement, Suga told a news conference when asked to comment on Schieffer's remarks. "Our basic policy is that this issue should not be made an either diplomatic or political issues."

The victims, known as "comfort women," were forced into military brothels for Japanese troops during the war. Given the harsh conditions they faced, the women were often described as sex slaves by non-Japanese media.

The Kono statement has been regarded as a key and straightforward government statement admitting Japanese authorities' responsibility for forcing the women to provide sex at military brothels.

During the campaign last year for the presidency of the Liberal Democratic Party, Prime Minister Shinzo Abe, whose party was then the opposition, said he would issue a replacement statement. But after taking power in December, Abe has toned down his rhetoric and stopped specifically talking about revising the Kono statement.