China on Tuesday denounced Osaka Mayor Toru Hashimoto's remarks that the "comfort women" were necessary for Japanese soldiers during the war.

Chinese Foreign Ministry spokesman Hong Lei told reporters the conscription of the comfort women, using the Japanese euphemism for the girls and women rounded up and used as sex slaves for the Imperial forces across Japanese-occupied territories, was a grave crime committed by the wartime military and a major human rights violation of the victims' personal dignity, according to Xinhua News Agency.

"We are shocked and indignant at the Japanese politician's remarks, as they flagrantly challenge historical justice and the conscience of mankind," Hong said when asked to comment on the remarks by Hashimoto, who coleads Nippon Ishin no Kai (Japan Restoration Party), according to the Xinhua report.

"How Japan treats its past will decide its future," Hong said, adding that its neighbors, as well as the international community, will have to wait to see what choice Japan makes.

Hashimoto said Monday that he believes the system to recruit females into sexual servitude was "necessary to maintain discipline" in the Japanese military during the war.

Hashimoto told reporters at Osaka City Hall that the females who were forced into sexual slavery for the Japanese military during the war were "needed to provide rest to a group of brave soldiers who were exalted in the line of fire."

He said the comfort women system was born "as a tragic consequence of war" and it is necessary to understand the feelings of such victims and pay due consideration to them.