Chinese Foreign Ministry spokesman Hong Lei on Tuesday added support to new calls for Japan to apologize for forcing women into sexual slavery during World War II.

It was a serious crime against humanity for the Japanese military to enslave such "comfort women," Hong said at a regular press briefing.

He urged Japan to show respect for "comfort women" and handle historical issues with a responsible attitude.

During a meeting in Tokyo on Monday, former "comfort women" and their relatives from several countries demanded the Japanese government follow the 1993 "Kono Statement", compensate the victims and make a more explicit apology.

Japan should face up to its history of aggression and deeply introspect, Hong said when responding to a question.