China pledged to hold high the banner of peace but also vowed to resolutely safeguard its sovereignty and the post-war international order, according to a government work report delivered by Premier Li Keqiang at the parliament's annual session on Wednesday.

"We will safeguard the victory of the Second World War and the post-war international order, and will not allow anyone to reverse the course of history," Li told the country's lawmakers at the opening of China's top legislature annual session.

"This could be the first time these words appear in China's government work report," said Wang Jianxue, vice head of China Association of Historians Studying Modern Chinese Historical Materials.

"Obviously, it shows China's firm stance and its warning to Japan," he told Xinhua.

The latest move came amid the mounting tension between the two East Asian nations over the territorial and historical rows. Relations between them have reached a new low since Japan's "purchase" of the Diaoyu Islands in September 2012 despite China's protests.

China, one of the major founders of the post-war international order, set two new national days last month, to mark victory in the anti-Japanese war and to commemorate the 300,000-plus Nanjing Massacre victims and all those killed in the Japanese aggression against China during the Second World War.

"The post-war international order requires that Japan should restore all the territories it has stolen from China and the Japanese war criminals should be punished," said Yin Zhuo, director of the Expert Consultation Committee of the People's Liberation Army (PLA) Navy.

"When China's resolution to safeguard the post-war international order is reflected in the government work report, the country is reminding the whole world that to maintain peace and stability, such an order should be respected," added Yin, who is also a member of the National Committee of the Chinese People's Political Consultative Conference(CPPCC), China's top political advisory body, which is convening its annual session in Beijing.

The Japanese Prime Minister Shinzo Abe's visit at the end of last year to the Yasukuni Shrine, where Japan's war dead, including convicted war criminals, are honored, is a challenge to the post-war international order, said Chinese Embassador to Japan Cheng Yonghua, also a member of the CPPCC National Committee.

"When one is waving his fists while inviting you for a dialogue, will you accept it?" he said, referring to the Japanese government's recent call for "dialogue" with China.

China will resolutely safeguard its sovereignty, security and development interests, and fully protect the legitimate rights and interests of Chinese citizens and business overseas, Premier Li said in the report.

China, which needs a long-term stable international environment for its modernization, will unswervingly follow the path of peaceful development and implement a win-win strategy of opening up, he told the nearly 3,000 deputies to the National People's Congress.

"We will strengthen friendship and deepen mutually beneficial cooperation with our neighbors," Li added.

The country will play a constructive role in resolving global and hotspot issues and work to make the international order more just and equitable, he pledged.