BEIJING -- President Xi Jinping criticized people who "beautify the history of aggression" as China on Monday marked the 77th anniversary of the start of a war with Japan amid rising tensions between Beijing and Tokyo.

This year's unusually high-profile commemoration of the 1937 Marco Polo Bridge Incident, including a nationally televised speech by Xi, comes amid an anti-Japanese propaganda campaign by Beijing.

The two governments are involved in a dispute over ownership of uninhabited islands in the East China Sea. China has expressed unease about Japan's reinterpretation of its pacifist constitution to ease restrictions on military activity. While the change has met with opposition within Japan, it has been supported by the United States and Australia, where Japanese Prime Minister Shinzo Abe was due to visit Monday.

"Unfortunately, nearly 70 years after the victory of the Chinese war of resistance against Japanese aggression and the anti-Fascist war, there is still a minority group of people who ignore historical facts, who ignore the tens of thousands of lives lost in the war, who go against the tide of history and deny and even beautify the history of aggression and harm international mutual trust and create regional tension," Xi said at a ceremony at suburban Beijing's Lugou Bridge, called the Marco Polo Bridge in the 1930s.

Asked about the commemoration, Japan's chief government spokesman, Yoshihide Suga, said China's attempt to dredge up wartime history and turn it into an international issue was unnecessary and "not helpful at all in building peace and co-operation in the region."

Suga said Japan has been recognized by the international community for being a peaceful nation since the end of World War II.

"We will continue our contribution to international peace and prosperity and to building a forward-looking relationship," he said.

Rana Mitter, a professor of Chinese history and politics at Oxford University, said Xi's speech fit into a pattern of attempts by China to highlight Chinese wartime resistance against Japan to "inspire patriotic fervour."

"It's really part of a growing tendency that we have seen, notably in the last few months, of attempts by China and the Chinese leadership to use events from the Second World War period to make points about contemporary geopolitics, particularly if they relate to Japan," he said.

Xi unveiled a commemorative sculpture based on a military medal at the Museum of the War of the Chinese People's Resistance Against Japanese Aggression, according to the official Xinhua News Agency.

After Xi spoke, a group of schoolchildren at the event chanted a promise to "remember history, cherish peace, not forget the shame of the nation and realize the Chinese dream."

In 1937, Japanese forces that had been in China's northeast since 1905 provoked a clash with Chinese soldiers at the Marco Polo Bridge by trying to enter the city of Wanping near Beijing. The fighting is regarded as the first battle of the second Sino-Japanese war, which lasted until Japan's defeat by the Allies in 1945.

China and Japan are now linked by billions of dollars in trade, investment and aid, but the ruling Communist Party uses state media and school history textbooks to keep alive anti-Japanese sentiment.

Relations worsened after Abe visited a shrine in Tokyo late last year that honours Japan's war dead, including convicted war criminals.

Soon after, officials at Japanese broadcaster NHK drew fire when one denied that the 1937 massacre in Nanjing of thousands of Chinese civilians by Japanese soldiers happened and another downplayed the Imperial Army's use of sex slaves.

In recent months, Beijing has tried to draw foreign attention to Japanese wartime aggression.

Last month, the government said it was applying to the U.N. cultural organization UNESCO to have 11 sets of documents relating to the Nanjing Massacre, including diaries, photographs and testimonies that depict Japan's brutality, declared important historical material.

Last week, China posted documents online that it said were personal accounts of wartime atrocities committed by Japanese in China.

On Sunday, China launched a website to promote commemoration of the Nanjing Massacre, also known as the Rape of Nanking.

Throughout the day Sunday, China Central Television's hourly news showed the recollections of a sobbing 85-year-old man of being forced to work in a Japanese iron mine during the war. Yu Mingting spoke about harsh living conditions and said when there was no room to bury the bodies of dead Chinese, Japanese poured gasoline on them and burned them.

On Monday, state television showed scenes from a 1956 trial of Japanese war criminals, with victims angrily and tearfully recounting their experiences.