Japanese Prime Minister Yoshihiko Noda on Friday said Japan "will take all possible measures to ensure security" after two Chinese surveillance ship fleets started patrol and law enforcement around Diaoyu Islands and its affiliated islets on Friday morning, the Kyodo news agency reported.

China Marine Surveillance No 15. [File photo]

The Japanese government has also set up a special office to deal with the particular issue at the crisis management center at the prime minister's office, said the report.

The Chinese surveillance ships arrived at waters around Diaoyu Islands and its affiliated islands early Friday morning.

It is the first time for Chinese surveillance ships to patrol there after the Chinese government announced on Monday the base points and baselines of the territorial waters of the Diaoyu Islands and their affiliated islets, as well as the names and coordinates of 17 base points.

These law enforcement and patrol activities are aimed to demonstrate China's jurisdiction over the Diaoyu Islands and its affiliated islets and ensure the country's maritime interests, according to a government statement.

The Diaoyu Islands and the affiliated islands have been an inalienable part of China's territory since ancient times, and China has indisputable sovereignty over them.

The Chinese government has repeatedly demanded that Japan immediately repeal its wrongful decision to "purchase" the Diaoyu Islands.

During consultations with Japanese diplomat Shinsuke Sugiyama in Beijing on Wednesday, Luo Zhaohui, head of the Chinese Foreign Ministry's Asian Affairs Department, said China will never recognize Japan's illegal seizure and so-called "actual control" of the Diaoyu Islands or tolerate any unilateral move made by Japan in regards to the Diaoyu Islands.

Luo demanded that Japan immediately correct its mistake, return to the consensus and understanding reached between the two sides and return to the track of negotiating a settlement of the dispute.?