China has submitted applications to UNESCO to preserve the archives that prove the suffering of "comfort women" and make it part of the UN body's Memory of the World program.

The application follows recent comments by leading Japanese politicians and academics casting doubt on the plight of the comfort women.

The Japanese Imperial Army had a policy of forcing women captured in occupied lands to work as sex slaves in military brothels.

Beijing's applications to UNESCO regarding the Nanjing Massacre and comfort women aim to "remember the history, cherish the peace and avert similar inhuman atrocities from taking place again", Foreign Ministry spokeswoman Hua Chunying said on Tuesday.

The Memory of the World program is an international initiative launched to safeguard the documentary heritage of humanity and protect experiences from being lost through neglect or denial.

Zhou Yongsheng, a professor of Japan studies at China Foreign Affairs University, warned that revisionist remarks within Japan are "rampant" and many leading figures have attempted to deny the history of the comfort women.

"They deny it to defend or make light of Japan's history of military aggression. We should have zero-tolerance for this," Zhou said.

Public debate was further heated in January after Japanese public broadcaster NHK's newly appointed head Katsuto Momii stated that comfort women existed in any country that was at war, not just Japan, but also France and Germany.

Momii even targeted South Korea for continuing to call for compensation for the women.

Eighty-nine wartime documents were made public in April by the Jilin Provincial Archives to further prove that forcing women into sex slavery were sanctioned by the Japanese army in Asian countries.

Su Zhiliang, director of the China Sex Slave Research Center and a professor of history at Shanghai Normal University, underscored the urgency of applying for the UNESCO program.

"The historical archives not only prove that it was the Japanese government and its army that conducted the sexual slavery, but also showed that it was widespread behavior," Su said at a recent seminar.

There was a stark example of revisionist voices at the highest levels on Monday when Japanese Prime Minister Shinzo Abe explicitly denounced the former chief cabinet secretary Yohei Kono and the "Kono Statement". In the statement, made more than 20 years ago, Kono apologized for Japan's wartime atrocities regarding the comfort women.

Abe criticized Kono on Monday and said that Kono's statement "left huge hidden trouble for future generations", Japan's Kyodo News Agency reported.