MANILA- The Philippines should protest China's recent construction efforts on the Fiery Cross Reef, locally known as the Kagitingan Reef in the West Philippine Sea, Supreme Court Justice Antonio Carpio said Thursday.

Carpio, a known advocate of Manila's rights in the disputed waters, said the Philippine government should file a note verbale over China's building of a maritime rescue center on the reef.

"That’s an exercise of administration and we should contest that because under our law that’s Philippine territory," Carpio told reporters.

"If a foreign country will say 'we will use this as a rescue center' which they should not do without our approval because that’s ours so we should protest,” he added.

Beijing had asserted it has the right to build on the reef, which it claims as its own.

"China carrying out peaceful construction on its own sovereign territory is only to contribute more to the region's peace, maritime safety, disaster prevention, ocean research, and search and rescue," Chinese Foreign Ministry spokesman Lu Kang said earlier this month.

• China defends construction activities on Fiery Cross Reef

If the Philippine government refuses to protest China's recent activitiy, Carpio said it would tantamount to waiving Manila's sovereign rights over the area.

“We should be wary of that because that’s an exercise of sovereignty or sovereign rights," he said.

The Philippines and China have long sparred over the South China Sea, but relations have improved considerably under President Rodrigo Duterte.

China has assured the Philippines it will not occupy new features or territory in the South China Sea, under a new "status quo" brokered by Manila as both sides try to strengthen their relations.

-report from Willard Cheng, ABS-CBN News