The spending, which opposition lawmakers say will be used for U.S. weapons, falls well short of the government's proposed budget of nearly $40 billion.
Former Defense Ministers Wei Fenghe and Li Shangfu were once members of China's powerful Central Military Commission, the body that oversees the country's military.
The Chinese drills included live-fire shooting, sea-air coordination, rapid maneuvers and maritime replenishments to test integrated joint combat capabilities.
