KUALA LUMPUR: China on Sunday told other countries not to "deliberately stir up trouble" in the disputed South China Sea, while insisting it has no intention of militarising the strategically vital area even though it has increased construction activities there.

Deputy Foreign Minister Liu Zhenmin reiterated China's position that its construction of artificial islands in the sea was designed to "provide public service" to the region by helping ships and fishermen and disaster relief efforts. This also includes military facilities to protect the islands and reefs, which are located far from mainland China, he said.

Since 2013, China has accelerated the creation of new outposts by piling sand atop reefs and atolls, and then adding buildings, ports and airstrips big enough to handle bombers and fighter jets — activities seen as an attempt to change the territorial status quo by changing the geography.

"One should never link the military facilities with efforts to militarise the South China Sea," Liu said. "This is a false argument. It is a consistent Chinese position to firmly oppose the militarisation of the South China Sea."

Other countries "should not deliberately stir up trouble but contribute to the peace and stability of the region," he said.

Although Liu's statement broke no new ground — China has said this in various ways before — the setting for his remarks was significant: an Asian summit also attended by President Barack Obama, whose administration has backed the Philippines and other Southeast Asian countries who have long-standing disputes with China in the South China Sea.

Liu's comments also serve to send a notice to China's rivals in the region that it will not back down from its position on the resource-rich sea, irrespective of pressure from the United States. While it opposes any US military incursion, China sees its own military presence there as justifiable.

Liu is at the summit accompanying Chinese Premier Li Keqiang.

At a separate news conference, Obama said the issue was a "key topic" at the summit of 18 countries that included China, as well as at a separate summit he had with leaders of 10 Southeast Asian countries.

"Many leaders spoke about the need to uphold international principles, including the freedom of navigation, and overflight and the peaceful resolution of disputes," Obama said.

"My fellow leaders from Japan, Australia and the Philippines have reaffirmed that our treaty alliances remained the foundation of regional security. The United States is boosting our support for the Philippines maritime capabilities and those of our regional partners," Obama said. The other claimants in Southeast Asia are Malaysia, Vietnam and Brunei.

The US and others have called on Beijing to halt the construction, saying they are destabilising an increasingly militarised region. Washington angered China by sending a warship inside a 12-nautical-mile (22-kilometer) territorial limit around Subi Reef in the Spratly Islands archipelago, where China and the Philippines have competing claims.

Liu called the USS Larsen's voyage last month a "political provocation."

"Is this a trend of militarisation that calls for our alert?" Liu asked. "We hope regional countries and those outside the region will make positive and constructive contribution to our efforts to maintain peace and stability in the South China Sea. Don't look for trouble."

He said out of the scores of islands, reefs and atolls in the vast sea, China has occupied only seven small islands and reefs in waters under its jurisdiction. Without naming any country, he accused three of them of occupying 42 "illegally." One of them, he said, controls 29, another one eight and the third country five.

With the waterway a crucial trade passage, he said freedom of navigation and peace and security of the area are crucial to China's economic expansion.

Liu denied allegations that China is waiting to complete its construction activities in the sea before agreeing to a binding code of conduct, in a move to tie the hands of its rival claimants.