Washington has lodged a protest against China through diplomatic channels, Pentagon press secretary Rear Adm. John Kirby said on Friday.

He said a Chinese fighter jet had conducted a "dangerous intercept" of a US Navy aircraft and conducted an acrobatic "barrel roll" maneuver around it in international air space, apparently in a way that showed that the plane was armed.

The intercept took place on Tuesday 200 km east of Hainan Island. According to information provided by Kirby, the fighter jet flew as close as 7 to 10 meters close to the P-8 Poseidon maritime patrol plane.

At a news briefing in Massachusetts, where President Barack Obama is vacationing, Ben Rhodes, deputy national security adviser for strategic communications, called the intercept "a deeply concerning provocation" and suggested it could set back efforts to improve relations.

"What we've encouraged is constructive military-to-military ties with China, and this kind of action clearly violates the spirit of that engagement," Rhodes told reporters.

US-Chinese military ties were greatly strained in 2001 when a Chinese fighter jet collided with a US Navy surveillance aircraft off Hainan. The Chinese pilot died in the collision and the navy plane had to make an emergency landing. "In the longer term, the incident has implications for the right of US and other nations' aircraft to fly in international airspace near China," concluded a Congressional Research Service report for US Congress titled, "China-US Aircraft Collision Incident of April 2001" from October 2011.

sb/rc (AP, Reuters, AFP)