Tokyo is "attempting to deny and even beautify" the country's history of militarism and aggression, the Foreign Ministry said, criticizing remarks by a public Japanese broadcaster.

"The alarm bell of history should ring constantly, and the historical lessons should be taken," Foreign Ministry spokeswoman Hua Chunying said on Monday, after Naoki Hyakuta, best-selling author on wartime suicide fighter pilots and now a governor of Japanese broadcaster NHK, said last week that the Nanjing Massacre in 1937 "never happened".

Hyakuta also claimed that the United States staged the postwar trial of Japanese leaders to cover up its own war crimes, including the atomic bombings of Hiroshima and Nagasaki.

Local US embassy criticized the comment as "preposterous".

Hyakuta's remarks came after the new chief of the NHK, Katsuto Momii, when asked about "comfort women" who were forced to have sex with Japanese soldiers before and during World War II, said such institutions existed in "every country" and that it is only considered wrong based on "today's morality".

Remarks by NHK executives have echoed "a range of erroneous positions recently made by the Japanese side", and such remarks aim to whitewash the militaristic past and challenge the result of World War II and the postwar international order, Hua said.

Hua said Japanese right-wing forces are "explicitly turning back the wheel of history", and the international community should remain on high alert over the impact of their efforts on regional peace and stability.

The Associated Press said on Sunday that minutes of a recent governing board meeting of NHK seem to back up suspicions that Japanese Prime Minister Shinzo Abe, despite his denials, is "trying to use Japan's news giant to promote his nationalist agenda".

Gao Hong, a senior expert on Japanese studies at the Chinese Academy of Social Sciences, said Abe and his followers are now trying to distort the public's understanding of history.

"They have planned to create ambiguity and impose ludicrous logic regarding the nature of the militaristic history," Gao said.

Yasuhiko Tajima, a media law professor at Sophia University in Tokyo, was quoted by AP as saying: "Apparently NHK is leaning toward the government, and increasingly neglecting its responsibility to check authority.

"I even feel democracy is at risk."

Experts said historical facts are undeniable.

Ben Dorfman, an associate professor of cross-cultural history at Aalborg University in Denmark, told Xinhua on Saturday that the Nanjing Massacre was written in world history books.

He mentioned two books - A History of the World from the 20th to the 21st Century published by Routledge and History of World Societies by Houghton Mifflin Company, which are required reading for freshmen at the university.

History books record Japanese troops' brutal behavior, including rape and looting, after Nanjing fell in December 1937, with photographs.

Zhu Chengshan, curator of the Nanjing Massacre Memorial Hall, said: "History is history and cannot be changed."

Documents show that Japan occupied Nanjing on Dec 13, 1937, and in the following six weeks the army committed arson and looted the city, killing more than 300,000 civilians and unarmed soldiers.

Contact the writer at zhangyunbi@chinadaily.com.cn