President Duterte on Monday said he was ready to send military ships to assert the country’s claim in the West Philippine Sea should China start drilling for oil and mineral resources in the disputed waters. Speaking publicly for the first time on the sea row with China since its militia vessels started massing at Julian Felipe (Whitsun) Reef in March, Mr. Duterte said he was “not so much interested in [China] fishing [within Philippine waters]. “(B)ut when we start to mine, when we start to get whatever it is in the bowels of the China Sea, our oil, then by that time I will send my gray ships there to stake a claim.”

Salaverria, L. B., Ramos, M., Corrales, N., & Gascon, M. (2021, April 21). Du30 to send warships if China drills for 'our oil'. Philippine Daily Inquirer, p. A3.