A senior official from the Philippines again warned Beijing China that the continued incursion of Chinese vessels into its waters could ignite "unwanted hostilities."
The statement made by one of President Rodrigo Duterte's top aides effectively intensifies the already escalated tensions between the two nations over the contested waters.
On Tuesday, Duterte's top legal counsel, Salvador Panelo, said China's "present territorial incursion" is significantly straining the relations between the two nations. Panelo said both nations likely do not want to trigger "unwanted hostilities."
"The matter of territorial dispute has to be resolved in the diplomatic negotiating table or by the dictates of international law," Panelo said.
Philippine Navy patrols initially discovered more than 200 Chinese fishing boats parked along Whitsun Reef on March 7. The contested reef is located just 320 kilometers (199 miles) west of Palawan Island and within the country's exclusive economic zone.
Last week, officials said that patrols had spotted several illegally built structures along the reef. Some of the fishing boats, allegedly manned by Chinese military personnel, have since scattered across the Spratly Islands.
Officials have repeatedly called on China to withdraw their "maritime militia vessels" from the area. Officials said the incursion into its exclusive economic zone is illegal as per the terms set by the International Court of Arbitration at The Hague.
China responded to the Philippines' call by insisting that the boats were only parked at the reef to shelter from bad weather. China currently claims sovereignty over much of the South China Sea, including parts that are within the exclusive economic zones of countries such as Vietnam, Malaysia, and Brunei.
Duterte, who has fostered warmer ties with China than previous administrations, has personally expressed concerns over the arrival of the flotilla. Duterte has not yet publicly addressed the issue and left most of the talking to his foreign and defense ministers.
Defense Secretary Delfin Lorenzana had a much tougher stance, stating that China's recent actions only reveals its intention of occupying the West Philippine Sea.
Lorenzana said that he was "no fool" to believe any of China's explanations on why the boats were there. He said that the Chinese should immediately "get out" of the country's territory.