Chinese officials also rejected that allegation and complaints from the Philippines about what Manila considers illegal Chinese intrusions into its waters. China's ambassador to the Philippines said the South China Sea is Beijing's territory and has been for centuries, but Liu Jianchao said Thursday in Manila that China will adhere to a 2002 agreement on developing the region.

The Philippines, Vietnam, Brunei, Taiwan and Malaysia all claim parts of the South China Sea and scores of uninhabited islets and outcroppings in the region. In recent months, the Philippines and Vietnam have reported several incidents involving Chinese vessels within their 370-kilometer maritime exclusive economic zones.

The recent incidents are raising alarm among Southeast Asian nations, despite Chinese assertions that it favors peaceful economic cooperation in the South China Sea, and promises it will not resort to force to defend its interests in the region.

Both the Philippine and the Vietnam governments say they intend to defend their territorial waters. Vietnam's Prime Minister Nguyen Tan Dung, in a report issued Thursday, said his country is prepared to “struggle against intrusion” into its waters.

The United States has called on all parties with claims in the South China Sea to resolve disputes peacefully and to ensure freedom of navigation in the crucial shipping route. Beijing says it will discuss disputes with other claimants bilaterally, but members of the Association of Southeast Asian Nations want multilateral talks.