File photo taken on a marine surveillance plane B-3837 shows the Diaoyu Islands and nearby islands.Photo:Xinhua

China lodged solemn representations to Japan on Sunday after five Japanese lawmakers reportedly trespassed into waters near the Diaoyu Dao for a maritime "inspection." Experts noted that Japan's action is a deliberate provocation against China, aimed at heightening tensions in East Asia and jeopardizing regional peace and stability.

According to media reports, the Japanese lawmakers trespassed into the waters near the Diaoyu Dao, also known as Diaoyu Islands, for the marine "inspection" on Friday, and they claimed they should land on the islands for investigations. 

In response to Japan's provocative actions, a spokesperson of the Chinese Embassy in Japan said on Sunday that China has lodged solemn representations with Japan, and the China Coast Guard (CCG) has taken measures against it in accordance with the law.

The Diaoyu Dao and its affiliated islands are an inherent part of China's territory, and China's determination and will to safeguard territorial sovereignty and maritime rights are unwavering, the embassy said.

"China strongly urges Japan to stop all political provocations, on-site disturbances and media hype, and return to the correct track of managing differences and disputes through dialogue and consultation to avoid further escalation of the situation," the spokesperson said.

The latest move by Japan is a blatant provocation against China, and is aimed at escalating tensions in the East Asia region, Lü Chao, a research fellow at the Liaoning Academy of Social Sciences, told the Global Times on Sunday.

"The Japanese cabinet, in particular, allegedly went so far as to claim [they could] land on the island, clearly demonstrating their intension to provoke China in terms of territory issue," Lü said. He noted that Japan deliberately wants to worsen the situation in the region, especially as the lawful patrols of the CCG around the Diaoyu Dao have become routine, with the latest one conducted on April 12.

Lü said that generally, Japanese lawmakers tend to take actions near the Diaoyu Dao during times when Japan is adopting a firm stance toward China and aligning with the US' strategy to form a confrontation with China in the Asia-Pacific region.

"The latest provocation from Japan is a common way for them to divert from domestic conflicts, given the current significant problems in both politics and the economy in Japan," Lü said.

The Chinese Foreign Ministry has stated that Diaoyu Dao and its affiliated islands are China's inherent territory. China will take firm measures against illegal moves that violate China's sovereignty, and China stands ready to continue properly handling maritime issues with parties concerned through dialogue and consultation and jointly upholding peace and stability in the South China Sea. 

"In the meantime, no one should violate China's territorial sovereignty and maritime rights and interests, and China remains steadfast in safeguarding our lawful rights," the ministry said.

In light of Japan's persistent provocative actions, China must firmly take countermeasures and should not tolerate Japan's attempts to stir up tensions over the Diaoyu Dao, Lü said. "China must consistently assert to Japan and the international community that the Diaoyu Dao belongs to China, and this reality is non-negotiable. China will also take all necessary measures to put an end to Japan's aggressive behavior toward China," he said.