MANILA -- The Philippines will not allow oil and gas deposits in the South China Sea to be harvested "unilaterally," Foreign Affairs Secretary Alan Peter Cayetano said Tuesday.

Former President Benigno Aquino had said that Manila had "no obligation" to share resources with Beijing, as incumbent President Rodrigo Duterte worked on possible joint exploration with China.

Aquino initiated an arbitration case against China, which the Philippines won less a month after Duterte took over. Duterte refused to flaunt the ruling and instead sought closer economic and diplomatic ties with China.

"If there are living and non-living resources in the West Philippine Sea and we can come up with a framework that is win win win, why not?" Cayetano told reporters.

"If not, it is our job to preserve, to make sure that the environment is not destroyed and that oil and gas is not harvested unilaterally at expense of the other claimants," he said.

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"If any country, including China, is willing to give us in disputed areas the same (share) that we got in Malampaya, how can anyone argue that we lost our sovereign rights?" Cayetano said.

He was referring to the Malampaya gas field, where the Philippines has a 60-percent share in revenues.

Joint explorations with China in disputed waters could "somehow give up" the Philippines' arbitration win, analysts said.

• Joint exploration with China would 'somehow give up' arbitration ruling: analyst