A key member of the U.S. Congress who is pressing the Japanese government to issue a thorough apology for the wartime "comfort women" system urged Tokyo on Thursday to view the matter as a human rights issue, not as a political spat between nations.

"The comfort women issue is not one of pitting Japan against South Korea. There are fewer than 100 former comfort women survivors. Japan needs to offer a formal and unequivocal apology and memorialize the issue in its textbooks," Mike Honda, a Democratic congressman from California's Silicon Valley area, said during a telephone news conference.

Honda was behind a U.S. House of Representatives nonbinding resolution in July 2007 that called on Japan to formally acknowledge and accept historical responsibility in a clear and unequivocal manner for the military's coercion of young women into sexual slavery during its colonial and wartime occupation of Asia and Pacific islands from the 1930s to the end of World War II.