BEIJING - The People's Daily, the flagship newspaper of the Communist Party of China, has said the Diaoyu Islands issue concerns China's territorial sovereignty and China will not compromise even with "half steps".

Japan has said it wants to mend relations with China but the Japanese government continues to insist that tough measures will be used to settle territorial issues, according to the newspaper commentary on Sunday.

China asked Japan to immediately stop all acts that harm China's territorial sovereignty, Foreign Ministry spokesman Hong Lei said late Saturday. This came after some Japanese people landed on the Diaoyu Islands Friday evening saying that they were "preventing Taiwan's activists from landing on the islets".

Japanese right-wing groups staged a mass anti-China demonstration in Tokyo on Saturday, chanting, "China, stop the invasion of Japan", vowing to defend the "Senkakus Islands" (Diaoyu Island and affiliated islets) and safeguard Japan's territorial integrity.

"Japan's aforementioned act is a severe infringement upon China's territorial sovereignty. They make trouble out of nothing and call white black," said the People's Daily commentary.

It said Japanese right-wing forces have long caused trouble on the Diaoyu Islands and that the Japanese government has misjudged the situation and colluded with the right wing, plotting to strengthen their control over Diaoyu Island and affiliated islets.

The "two-man act" played by the Japanese government and the right wing over the Diaoyu Islands issue was "not accidental", but an indication of the context of Japan's accelerated right-leaning tendency, toughened foreign polices and strained relations with its neighbors, the commentary said.

Japan's two-decade economic downturn has rapidly changed the power balance between China and Japan, plunging some Japanese people into frustration and anxiety and prompting them to hold a hard line as a political "magic weapon" to deal with China, it said.

"The severe situation for Sino-Japanese relations has been caused by Japan single-handedly," it said.

Not taking into account the resolute opposition and solemn representations by the Chinese side, the Japanese government's "illegal and ineffective purchase" of part of the Diaoyu Islands, which is China's inherent territory, severely infringes upon China's territorial sovereignty and seriously damages Chinese people's feelings, it said.

The "island-purchase" farce gets Japan into a passive situation, the article said, adding under increased pressure, it has expressed hope to repair Sino-Japanese relations via improved communication and bilateral talks.

However, it is not a mere lip service that gets things moving forward. The Japanese government must take "frank and practical actions" and fundamentally change its wrongful act if it really wants to mend bilateral relations.

"How will the Sino-Japanese relations be mended if Japan does not repent?" The article said Japan must immediately cease actions infringing upon China's territorial sovereignty.

China will continue to take measures to firmly safeguard its sovereignty over the Diaoyu Islands, the article said, adding the government and people will not compromise on such issue.