South China Sea dispute

The United States warned on Thursday it would not tolerate efforts to control sea and air routes in the South China Sea, as Southeast Asian nations debated how hard to pressure Beijing on its island-building. Beijing claims control over nearly the entire South China Sea, a key shipping route thought to hold rich oil and gas reserves.

Vietnam, the Philippines, Malaysia and Brunei -- all ASEAN members -- also have various claims, as does Taiwan, many of which overlap. US says China's construction of facilities for "military purposes" on man-made islands was raising tensions and risked "militarisation" by other claimant states.

The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around 3,500,000 square kilometres. The area's importance largely results from one-third of the world's shipping transiting through its waters, and that it is believed to hold huge oil and gas reserves beneath its seabed.

The minute South China Sea Islands, collectively an archipelago, number in the hundreds. The interests of different nations include acquiring fishing areas, potential exploitation of suspected crude oil and natural gas, and strategic control of important shipping lanes. The Spratly Islands are a disputed group of more than 750 reefs, islets, atolls, cays and islands in the South China Sea.

The archipelago lies off the coasts of the Philippines, Malaysia, and southern Vietnam. The Philippine military described reported Chinese construction on a reef in the disputed South China Sea as alarming Tuesday, and confirmed that Beijing may be constructing a second airstrip in the Spratly Islands.

In a recent report, Washington-based think-tank Center for Strategic and International Studies (CSIS) said that according to photos of Subi Reef, China may be preparing to set up a second airstrip in the islands, despite no actual paving being observed so far.

A 3,000-meter Chinese airstrip -- the largest in the region, where four other claimants have such structures -- is already in the “advanced stages of construction” at the Fiery Cross Reef. China is said to have built seven artificial islands in the strategically sensitive and economically critical South China Sea, alarming its neighbors and risking confrontation with the United States.