China's navy chief warned his US counterpart encounters between their forces could spiral into conflict, state media reported, two days after a US destroyer sailed close to Beijing's artificial South China Sea islands.

The comments by Admiral Wu Shengli, who commands the Chinese navy, were made in a video call with US Admiral John Richardson that lasted about an hour, Beijing's official Xinhua news agency said Friday.

They came after the USS Lassen guided missile destroyer sailed within 12 nautical miles of at least one of the land formations claimed by China in the disputed Spratly Islands chain.

Chinese authorities monitored and warned away the vessel, but did not otherwise intervene, although Beijing later summoned the US ambassador and denounced what it called a threat to its sovereignty.

"If the US continues to carry out these kinds of dangerous, provocative acts, there could be a serious situation between frontline forces from both sides on the sea and in the air, or even a minor incident that could spark conflict," Xinhua paraphrased Wu as saying.

"I hope the US cherishes the hard-won, good situation between the Chinese and US navies and avoids similar incidents from happening again," Wu added.

Beijing insists it has sovereign rights to nearly all of the South China Sea, a strategic waterway through which about a third of all the world's traded oil passes.

The disputed waters -- also claimed in part or in whole by Vietnam, Malaysia, the Philippines, Taiwan and Brunei -- have also become the stage for a tussle for regional dominance between Beijing and Washington, the world's two largest economic and military powers.

- Mounting tensions -

Tensions have mounted since China transformed reefs in the area into small islands capable of supporting military facilities, a move the US says threatens freedom of navigation.

Washington has repeatedly said it does not recognise Chinese claims to territorial waters around the artificial islands.

And on Friday, China rejected a ruling by an international tribunal based in The Hague that it could consider an action brought by the Philippines over the disputed islands.

A Pentagon spokesman said the US and Chinese commanders discussed "freedom of navigation operations, the relationship between the two navies including pending port visits, senior leader engagement and the importance of maintaining an ongoing dialogue" on the call.

A US defence official, speaking on condition of anonymity, said the Chinese had expressed no desire to cancel scheduled visits by Chinese ships to a Florida port next week, and that Admiral Harry Harris, the commander of the US Pacific Command, would still visit China.

"We look forward to continue this dialogue," the official said.

Harris is due in China on Monday for a three-day trip including meetings with senior Chinese military leaders, US Pacific Command said, adding that "candidly addressing and managing disagreements" was among the objectives.

A US official told AFP on Tuesday that the US Navy would send more warships to sail close to the controversial islets.

Top US, Chinese naval officers hold video talks
Washington (AFP) Oct 30, 2015 - The chief of US naval operations spoke with his Chinese counterpart via video on Thursday, two days after a US destroyer sailed close to artificial islands built by Beijing in the South China Sea.

The call between Admiral John Richardson and Admiral Wu Shengli, who commands the Chinese navy, lasted about an hour.

Pentagon spokesman Captain Jeff Davis said the men discussed "freedom of navigation operations, the relationship between the two navies including pending port visits, senior leader engagement and the importance of maintaining an ongoing dialogue."

Navy spokesman Lieutenant Tim Hawkins said the conversation was "professional and productive."

A US defense official, speaking on condition of anonymity, said the Chinese had expressed no desire to cancel scheduled visits by Chinese ships to a Florida port next week, and that an upcoming visit to China by Admiral Harry Harris, the commander of the US Pacific Command, would still take place.

"We look forward to continue this dialogue," the official said.

Harris is due in China on Monday for a three-day trip including meetings with senior Chinese military leaders, US Pacific Command said in a statement, adding that "candidly addressing and managing disagreements" was among the objectives.

The USS Lassen guided missile destroyer sailed within 12 nautical miles of at least one of the land formations claimed by China in the disputed Spratly Islands chain on Tuesday.

The move infuriated Beijing, which summoned the US ambassador and denounced what it called a threat to its sovereignty.

Davis said the sailing was not intended as a challenge to the sovereignty of "land features" in the South China Sea.

The "US takes no position in competing sovereignty claims," he said.

Wu and Richardson agreed to speak again via video conference later this year, he added.

Tensions have mounted since China transformed reefs in the area -- also claimed by several neighboring countries -- into small islands capable of supporting military facilities, a move the US says threatens freedom of navigation.

Washington has repeatedly said it does not recognize Chinese claims to territorial waters around the artificial islands.

A US official told AFP on Tuesday that the US Navy would send more warships to sail close to the controversial islets.