US Hits at China over Spy Plane 'Provocation'

The Obama administration condemned the latest incident, with Deputy National Security Adviser Ben Rhodes saying that it was a "deeply concerning provocation".

"What we have encouraged is constructive military-to-military ties with China and this type of action ... clearly violates the spirit of that engagement, and we have made our concerns known directly to Beijing," he said.

Rear Admiral John Kirby, the US defence press secretary, said that a Chinese fighter pilot performed acrobatic maneuvers around the Navy patrol plane, and flew a few metres from the US jet, Al Jazeera reported.

Kirby said the US lodged a formal diplomatic protest with Beijing over the incident, which took place on Tuesday about 215km east of Hainan Island, site of a sensitive Chinese submarine base.

Kirby said the Chinese fighter jet made several passes at the P-8 Poseidon anti-submarine and reconnaissance plane, crossing over and under it. At one point, the jet flew wingtip-to-wingtip (about 9 metres) from the Poseidon, then performed a barrel roll over the top of it, he said.

"The Chinese jet also passed the nose of the P-8 at 90 degrees with its belly toward the P-8 Poseidon, we believe to make a point of showing its weapons load," Kirby said.

The US Navy's P-8 Poseidon aircraft are designed for long-range missions including intelligence collection and reconnaissance.

"This kind of behaviour not only is unprofessional, it's unsafe," he said. "And it is certainly not in keeping with the kind of military-to-military ... relations that we'd like to have with China."

The United States and China have differing views about the legality of US military overflights in much of the region as a result of China's broad territorial claims and differing interpretations of rights conveyed under the Law of the Sea treaty.