China on Saturday called United States' criticism of an approach by one of its jets to a U.S. Navy patrol plane off the Chinese coast earlier this week "completely groundless" and said its pilot had maintained a safe distance from the US aircraft.

The strongly-worded statement attributed to Ministry of National Defense spokesman Yang Yujun was a response to a diplomatic complaint the Pentagon filed with Beijing on Friday.

The complaint concerned an August 19 encounter about 135 miles east of China's Hainan Island in which a Chinese fighter jet came within yards of a US P-8 Poseidon anti-submarine and reconnaissance plane and, the US claimed, performed acrobatic maneuvers around it.

In its statement, the Chinese defense ministry said the J-11 jet was conducting routine checks and described the pilot's actions as professional.

The United States' frequent short-range reconnaissance missions threatened the safety of both militaries, it said.

It urged the U.S. to reduce short-range reconnaissance against China and to respect international law and conventions.