China will take countermeasures if an arms buildup by the United States in the South China Sea poses a security risk to Chinese territory, experts said on Tuesday regarding reports of US plans to deploy more weapons in the area.

The website of the US Navy Times newspaper reported on Dec 31 that the Nimitz class supercarrier USS Carl Vinson and its escorts, along with 7,500 sailors, are set to deploy late this week for a Western Pacific cruise.

In another report, the National Interest magazine said on Jan 1 that senior US Army and Pentagon strategists are considering ways to use existing weapons platforms in new ways - including the possible placement of mobile artillery units in areas of the South China Sea to, if necessary, function as air-defense weapons to down rockets and cruise missiles.

The magazine said officials had made no decisions along those lines, but that it is "one of the things being considered".

"At the same time, Pentagon officials have publicly stated the US will continue 'freedom of navigation' exercises wherein Navy ships sail within 12 miles of territory claimed by the Chinese.

"In addition to these activities, it is entirely possible the US could also find ways to deploy more offensive and defensive weapons to the region," the article said.

"Apparently, the US military wants to find new approaches to the South China Sea to contain China," said Zhao Xiaozhuo, director at the Center on China-US Defense Relations at the People's Liberation Army Academy of Military Science.

"We will see how long the USS Carl Vinson will stay here. Is it just a cruise or a long stay or to hold exercises? And how far is it from the Chinese-occupied islands? We'll keep a close watch," he said.

Zhao said the reason to implement mobile artillery units would be to quickly intervene in any conflict near South China Sea islands.

Zhang Junshe, a senior researcher at the PLA Naval Military Studies Research Institute, said once US arms implementation in the South China Sea poses a threat to Chinese islands, facilities or personnel, "China will certainly take countermeasures".

On Monday, China's J-15 fighters, flying from the country's sole aircraft carrier, the Liaoning, conducted flight exercises in "complex sea conditions", the Chinese Navy said on its microblog that day.

The Liaoning and its accompanying fleet entered the Pacific through the Miyako Strait for the first time on Dec 25 for a routine exercise in the Western Pacific, the Navy said.

lixiaokun@chinadaily.com.cn