Bangkok, May 30 (EFE).- The U.S. government said Saturday in Singapore that it is “deeply concerned” about Chinese island-building and military activity in the resource-rich South China Sea and urged all countries involved to halt their land-reclamation efforts to avoid an escalation of tensions in the region.

“First, we want a peaceful resolution of all disputes and an immediate and lasting halt to land reclamation by any claimant,” U.S. Defense Secretary Ashton Carter said at the May 29-31 Shangri-La Dialogue security policy forum in Singapore.

“We also oppose any further militarization of disputed features.”

Brunei, China, Philippines, Malaysia, Taiwan and Vietnam have laid partial or total claim to more than 100 previously uninhabited reefs and atolls in the Spratly Islands in the South China Sea, a region that is rich in oil and gas reserves, an important fishing ground and a key maritime route.

U.S. officials say that over the past year and a half China has reclaimed more than 2,000 acres of land that it plans to use to build strategic buildings and a runway for planes to land.

“Turning an underwater rock into an airfield simply does not afford the rights of sovereignty or permit restrictions on international air or maritime transit,” Carter was quoted as saying Saturday by the Singapore-based English daily The Straits Times.

Carter said the United States is “deeply concerned” about growing Chinese military activity in the region and warned of the “potential for these activities to increase the risk of miscalculation or conflict.”

But Col. Zhao Xiaozhuo of China’s Academy of Military Science said at the meeting that his country’s construction activity is reasonable and justified and said freedom of navigation in the South China Sea is not at risk.

China has placed at least two mobile artillery guns on one of the artificial islands it is building in the South China Sea, according to Pentagon officials.

Carter said earlier this week that the United States will not recognize Chinese claims to newly built territories and that U.S. military aircraft and warships will continue to operate in the area.