BEIJING, China - CHINA’S newest city is a tiny and remote island in the South China Sea, barely large enough to host a single airstrip. There is a post office, bank, supermarket, and a hospital, but little else. Fresh water comes by freighter on a 13- hour journey from China’s southernmost province.

Welcome to Sansha, China’s expanding toehold in the world’s most disputed waters, portions of which are also claimed by Vietnam, the Philippines and other neighbours. Yesterday, as blustery island winds buffeted palm trees, a new mayor declared Sansha with a population of just 1,000 China’s newest municipality.

Beijing has created the city administration to oversee not only the rugged outpost but hundreds of thousands of square kilometres (miles) of water, aiming to strengthen its control over disputed — and potentially oil-rich — islands.

A spokesman for the Philippines Foreign Ministry said Manila did not recognise the city or its jurisdiction. Vietnam said China’s actions violated international law.

The city administration is on tiny Yongxing island, 350 kilometres (220 miles) southeast from China’s tropical Hainan Island. The Cabinet approved Sansha last month to “consolidate administration” over the Paracel and Spratly island chains and the Macclesfield Bank, a large, completely submerged atoll that boasts rich fishing grounds that is also claimed by Taiwan and the Philippines.

Vietnam and China both claim the Paracels, of which Yongxing, little more than half the size of Manhattan’s Central Park, is part. The two countries along with the Philippines, Malaysia, Brunei and Taiwan also claim all or parts of the Spratlys.

China claims virtually the entire South China Sea and its island groups, and its disputes occasionally erupt into open confrontation. The islands, many of them occupied by garrisons from the various claimants, sit amid some of the world’s busiest commercial sea lanes, along with rich fishing grounds and potential oil and gas deposits. China has approved the formal establishment of a military garrison for Sansha, though specific details have yet to be released.

Official broadcaster China Central Television aired yesterday morning’s formal establishment ceremony live from Sansha, with speeches from the city’s new mayor and other officials.

The Chinese flag was raised and national anthem played before plaques for the Sansha Municipal Government and the Sansha Municipal Committee of the Communist Party of China were unveiled on a white-columned government building.

Mayor Xiao Jie trumpeted Sansha’s important role in protecting China’s sovereignty. He said the designation of Sansha as a new city was “a wise decision made by the party and the government of China to protect the sovereign rights of China, and to strengthen the protection and the development of natural resources”.