China has raged at the United States for flexing its “gunboat muscles” in annual joint military exercises with the Philippines – warning Washington and its allies would only cause “division and turbulence.”

Xi Jinping‘s close ally Zhang Youxia, who leads Beijing’s Central Military Commission, issued a stern warning to the two nations as they started their three-week Balikatan, or “shoulder-to-shoulder”, drills.

This year’s exercise, which runs until May 10, is the first to be held beyond Manila’s territorial waters – and a time when tensions with China are especially high over control of the South China Sea.

The Philippines’s Coast Guard have repeatedly clashed with their Chinese counterpart in recent months, and for the first time will take part in the drills in an active role.

Zhang said the sea is not the right place to showcase one’s strength as he issued a severe warning to its neighbours and the US.

READ MORE: Desperate Putin insists ‘barbaric’ West trying to ‘escalate’ Ukraine war

Beijing has ignored rulings not in its favour, particularly in the South China Sea, where it is in dispute with five other parties over islands, waterways and undersea resources.

Zhang said China’s territorial sovereignty “brooks no infringement and its core interests cannot be challenged. We do not provoke trouble, but we will never flinch in the face of provocation.”

He added: “The Chinese military will resolutely defend the reunification and interest of the motherland.”

Zhang’s comments follow a major shakeup of the Chinese military in recent months that has seen the still-unexplained disappearance of former Defense Minister Li Shangfu and several top officers in the missile corps.