China's Ministry of National Defense on Thursday urged Japan to accelerate the disposal of the chemical weapons it abandoned in China and reflect on its historical responsibility.

Ministry spokesperson Zhang Xiaogang made the remarks at a regular press conference regarding the recent disclosure of multiple newly uncovered historical materials that further prove the crimes committed by the Japanese army during its invasion of China, including thousands of pages of documents and footage related to the germ warfare conducted by the notorious Unit 731.

The inhumane acts of aggression and heinous massacres committed by Japanese militarism have brought unprecedented disaster to the people of China and other Asian countries, Zhang said.

He stressed that Unit 731, in particular, had carried out the horrific germ warfare against the Chinese people, which flagrantly violated international law and is a monstrous crime against humanity.

"This history is an ironclad, undeniable, and indelible truth," Zhang said.