The government has weighed in again on Thursday over UNESCO's acceptance of Chinese records of a wartime atrocity, demanding that the United Nations' culture agency "swiftly improve" its procedures.

Culture minister Hiroshi Hase spoke up at UNESCO's General Conference after the body accepted for its Memory of the World program papers China submitted relating to the 1937 Nanking Massacre.

"We need to promote discussions to swiftly improve governance and transparency" of the program's register, Hase said.