There have been reports of the Japanese government trying to block China's effort to enter documents relating to the 1937 Nanjing Massacre into UNESCO's Memory of the World Register.
Through the Japanese embassy in China, Japan has asked the Chinese government to retract its nomination, according to a report by Asahi Shimbun, a Japanese news publication.
On Sunday, the International Advisory Committee began reviewing documents related to the Nanjing Massacre, as well as those relating to comfort women, those who were forced to be sex slaves for Japanese soldiers during World War II.
China has reportedly ignored several pleas coming from the Japanese government.
Japanese Prime Minister Shinzo Abe and Foreign Minister Fumio Kishida also reportedly expressed concerns regarding the nomination to the UNESCO secretariat.
Official from the Second Historical Archives of China Guo Biqiang said that the nomination would have significance to China if the documents are accepted into the Memory of the World Register.
"This year marks the 70th anniversary of the victory of the World Anti-Fascist War, as well as the Chinese People's War of Resistance against Japanese Aggression," said Guo. "It could remind us of remembering the history and cherishing peace."
According to China's Foreign Ministry spokesperson Hua Chunying, the documents were submitted to the UNESCO program "to prevent the miserable and dark days from coming back again."
The nominated documents are firsthand materials that recorded the 1937 Nanjing Massacre.
Since 1992, the UNESCO Memory of the World program has been registering dozens of projects to represent the "documentary heritage" of the world. These documents include Britain's 13th-century Magna Carta, the Diary of Anne Frank and an annotated copy of Karl Marx's Das Kapital.
Japanese Chief Cabinet Secretary Yoshihide Suga declined to comment on whether Japan had tried to contact committee members during a press conference on Friday.
Suga said that China's nomination would "unnecessarily emphasize a negative legacy from a certain period in the past involving Japan and China."