Senior military officer inspects Nansha Islands

A formation of the Nanhai Fleet of China's Navy on Saturday finished a three-day patrol of the Nansha islands in the South China Sea. [Photo/Xinhua]

A top military officer has made a rare visit to some of the islands in the South China Sea amid rising maritime tension caused by a recent US-Philippine joint patrol.

Vice-Chairman of the Central Military Commission Fan Changlong made the visit "in recent days" to China's Nansha Islands, according to a statement released by the Defense Ministry on Friday.

The commission, China's top military commanding agency with two vice-chairmen including Fan, is headed by President Xi Jinping.

The ministry said the construction projects are going smoothly.

Those projects, including lighthouses, weather stations, oceanic observation centers and research facilities, will provide public services for the international community.

The ministry's release did not name specific islands, but it said five lighthouses for navigation safety have been completed, and four of them are now operating.

The statement was released shortly before a visit by US Defense Secretary Ash Carter to the US aircraft carrier John C. Stennis on the final day of a joint US-Philippine military exercise.

At the closing ceremony, Carter told about 9,000 troops that the United States would back up the Philippines and other allies in the region.

Foreign Ministry spokesman Lu Kang said on Friday that in the past four decades, China and other countries have handled disputes through peaceful dialogue in the South China Sea region.

Measures taken by the United States should be constructive for resolution of disputes, Lu added.

Peng Guangqian, deputy secretary-general of the China Council for National Security Policy Studies, said that Vice-Chairman Fan's trip to the Nansha Islands is a necessary and proper reaction to some countries that are flexing muscles in the region.

"It has shown our determination, resolution and capability to protect our nation, which is the mission for the military," he said.

Li Jie, a senior expert at the Naval Military Studies Research Institute, said that through the US-Philippine joint patrols, the US has sent a hawkish signal on meddling in South China Sea affairs.

Richard Javad Heydarian, a security expert at Manila's De La Salle University, said that the US-Philippine joint patrols are more symbolic than substantive.

"It remains to be seen, however, how far America is willing to go to help the Philippines, but certainly pressure is building up in the US Senate and Pentagon for a more robust pushback against China," he said.

Wang Qingyun and Zhang Yunbi contributed to this story.