Ministry spokesman Hong Lei said the council's decision was "appreciated" and "welcomed".

"China accepts arctic states' sovereignty, sovereign rights and jurisdiction in the Arctic region and their leading role in the council," he said on the ministry's website. "The decision of the council will help China strengthen exchanges and co-operation with the relevant parties within the framework of the council, to contribute to the work of the council, promote peace, stability and sustainable development of the arctic region."

The milestone event was reported on the State Oceanic Administration's website in just one matter-of-fact sentence. Requests for comment were turned down by the administration and its polar affairs subsidiary, the Chinese Arctic and Antarctic Administration. "It is a diplomatic affair. We will not comment on it," an official said on Thursday.

A marine geologist with one of the oceanic administration's research institutes said that the marine authorities were unhappy because China had made a big compromise.

"We have tried to join the Arctic Council for more than a decade," he said. "The reason why we did not sign the agreement was because we had been asked to give up all possible claims and rights on key issues such as the management of natural resources and transport.

"You can tell from the one-sentence report how cold the [oceanic] administration is to the diplomats' success. No comment is as negative as a comment can get on such a crucial matter."

The Arctic Council was established in 1996 by eight permanent members - Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden and United States - that all touch the Arctic Circle, to manage affairs and resolve conflicts of interest in the region.

In addition to China, India, Italy, Japan, Singapore and South Korea were given observer status.

Marine geoscientist Professor Li Sanzhong , of the Oceanic University of China in Qingdao , Shandong , said there was an abundance of resources in the Arctic region, such as oil, natural gas and minerals.

"A substantial area of the Arctic region had not been legally claimed by any country," he said. "China has the need and technological ability to explore and mine these resources. It is definitely worth a try."

Another Chinese concern is the Northern Sea Route. With melting of permanent ice in the Arctic from global warming, more ships will be able to use the once-unnavigable route between Asia and Europe, making the journey much faster than the traditional route through the Malacca Strait and Suez Canal.

China is worried that the Northern Sea Route will be controlled by a few countries, as are the Malacca Strait and Suez Canal, and it had hoped to have a bigger say on Arctic matters to match its growing economic, political and military clout.

But China's willingness to intervene in Arctic affairs was met with strong opposition from some member countries, including Russia.

Zhang Guoqing, a researcher on regional affairs with the Chinese Academy of Social Sciences, told the that Russia was worried that an active Chinese role in the region would reduce its own Arctic influence.

"China is not far away from the Arctic," he said. "Once it enters, Russia's interests would be affected. The relationship between these two countries is very delicate because they all want to maximise their interests."

Russia's opposition to a bigger Chinese role in the Arctic had enraged many internet users in China, Zhang said. "Compared to member states, observer states have no rights on voting, organisation, decision making and especially the making of rules," he said. "[They] can only join some discussions and debates by expressing their wishes and opinions … the difference is huge."