China on Monday called on Washington not to pick sides in quarrels over the South China Sea, state media said, days after a US naval commander flew over the disputed waters.

US Pacific Fleet commander Admiral Scott Swift on Saturday made what the fleet called a "seven-hour maritime surveillance mission" over the South China Sea aboard a US P-8A Poseidon aircraft.

Swift also visited the Philippines, a close US ally and one of several countries locked in territorial disputes with China over competing claims to the Sea.

China's defence ministry responded by calling on the US to "take more actions to promote regional peace and stability, and not the opposite".

"We hope the US will abide by its promise not to take sides over South China Sea issues," it added in a statement reported by the Global Times newspaper.

China claims most of the South China Sea, overlapping with areas the Philippines, Brunei, Malaysia, Vietnam and Taiwan deem to be their territory.

The Philippines has been improving defence ties with the United States as the conflict has grown, and last week said it would open a US naval base that closed more than 20 years ago facing the Sea.

It was not stated which parts of the disputed waters Swift flew over in the flight, reported Sunday on the website of the US Pacific Fleet.