China plans artificial island in disputed Spratlys chain in South China Sea

China is looking to expand its biggest installation in the Spratly Islands into a fully formed artificial island, complete with airstrip and sea port, to better project its military strength in the South China Sea, a Chinese scholar and a Chinese navy expert have said.

The planned expansion on the disputed Fiery Cross Reef, if approved, would be a further indication of China's change of tack in handling long-running sovereignty disputes from a defensive stance to an offensive one, analysts said. They said it was seen as a step to the declaration of an air defence identification zone.

The Philippines last month protested against China's reclamation activities at nearby Johnson South Reef, site of a 1988 skirmish between the Chinese and Vietnamese navies that was triggered by China's occupation of Fiery Cross Reef.

With recent developments in the South China Sea having again focused the international spotlight on China, the analysts warned reclamation at the Fiery Cross atoll - which China, the Philippines and Vietnam all claim - would further strain Beijing's relations with neighbours.

The proposal to build an artificial island there had been submitted to the central government, said Jin Canrong , a professor of international relations at Renmin University in Beijing. The artificial island would be at least double the size of the US military base of Diego Garcia, a remote coral atoll occupying an area of 44 square kilometres in the middle of the Indian Ocean, Jin added.

The reef currently houses Chinese-built facilities including an observation post commissioned by Unesco's Intergovernmental Oceanographic Commission.

Li Jie, a naval expert from the Chinese Naval Research Institute, said the expanded island would include the airstrip and port. After the expansion the island would continue to house the observation post and to provide military supplies and assistance, he said.

A retired People's Liberation Army senior colonel, who spoke on condition of anonymity, said the construction of a landing strip on Fiery Cross Reef would allow China to better prepare for the establishment of an air defence identification zone over the South China Sea.

Watch: What is the East China Sea dispute about?

Beijing's declaration of such a zone over the East China Sea in December prompted concerns among Southeast Asian countries that a similar arrangement could be imposed in the South China Sea.

Fiery Cross Reef, known as Yongshu in China, Kagitingan in the Philippines and Da Chu Thap in Vietnam, is close to sea lanes and could serve as a strategic naval staging post, said Alexander Neill, a Shangri-La Dialogue senior fellow.

Jin said consideration of whether and how to go ahead with the Fiery Cross Reef proposal would depend on progress on reclamation at Johnson South Reef.

"It's a very complicated oceanic engineering project, so we need to learn from the experience" on Johnson South, Jin said.

Late last month, renditions of a proposed artificial island were circulated among Chinese media. Citing a report posted on the website of the Shanghai-based China Shipbuilding NDRI Engineering, the Global Times said the unidentified artificial island could include a landing strip and a 5,000-tonne berth.

Zhang Jie, an expert on regional security with the Chinese Academy of Social Sciences, said China had long been researching island reclamation. Institutes and companies had drafted various designs over the past decade, said Zhang, adding that she had attended deliberation of one proposal years ago.

"We had the ability to build artificial islands years ago, but we had refrained because we didn't want to cause too much controversy," she said.

However, this year had seen a "turning point" in which Beijing appeared to be making more offensive moves in the area, said Zhang, citing the recent deployment of an oil rig to disputed waters near Vietnam.

"Building an artificial island can no doubt provide supplies to ships and oil rigs nearby, but this would also cause very severe negative impacts in the region."

Such moves, she added, would further deepen mistrust among China's neighbours and cause instability in the region.

The Ministry of Foreign Affairs and Ministry of Defence in Beijing did not respond to requests for comment.