The 360-foot-long Shang-class submarine can carry torpedoes and ship-to-ship missiles with a maximum firing range of 25 miles.
The Chinese navy closes off 15,000 square miles in the East China Sea to perform live-fire drills as the U.S.-North Korea rivalry escalates.
A Chinese fighter jet flew as close as 20 to 30 feet to a P-8 Poseidon maritime patrol plane and did a barrel roll, the Pentagon says.
"To beef up military alliances targeted at a third party is not conducive to maintaining common security in the region," President Xi Jinping said in a speech
The U.S. made a rare foray into the East China Sea, drawing attention to the wide gap between American military abilities and those of China.