China on Wednesday rejected Japan's call for it to withdraw an application to register historic records of Japan's wartime sex slaves and the Nanjing Massacre with UNESCO.

"We will not accept Japan's unreasonable protest, and will not drop our application," said Chinese foreign ministry spokeswoman Hua Chunying at a daily news briefing.

Earlier on Wednesday, Japanese Chief Cabinet Secretary Yoshihide Suga said that Japan had lodged a protest over the application and had asked China to withdraw it.

However, Hua said that the aim of China's application is to firmly bear history in mind and cherish peace, respect human dignity and prevent anti-humane behavior from reoccurring.

On Tuesday, Hua confirmed that China had applied to UNESCO to list valuable historic documents relating to the 1937 Nanjing Massacre and Japan's wartime sex slaves, or "comfort women," on the Memory of the World Register.

China has been commemorating the 1937 Nanjing Massacre every year, during which Japanese troops killed, according to Chinese estimates, about 300,000 people in the city.

While there are controversies about the exact death toll, some conservative Japanese politicians and scholars deny a massacre ever took place.

Created in 1997, the Memory of the World Register protects documentary heritage.

Historians estimate that 200,000 women were forced into servitude by Japanese forces during World War II, most of whom were from countries invaded by Japan including China and South Korea.