The Philippines’ President also added he is “not so much interested now in fishing” after China sent fishing vessels with militia on board, but is more concerned about oil drilling.
Mr Duterte told reporters: “When we start to mine, when we start to get whatever it is in the bowels of the China Sea, our oil, by that time I will send my grey ships there to stake a claim.
“If they start drilling oil there, I will tell China, is that part of our agreement?
“If that is not part of our agreement, I will also drill oil there.
“If they get the oil, that would be time that we should act on it.”