The announcement came the same day that China's President, promoting peace and downplaying differences, arrived in Seattle to start a potentially pivotal U.S. visit.
A U.S. RC-135 aircraft operating above the Yellow Sea, approximately 80 miles east of the Shandong Peninsula, reported the September 15 incident after the Chinese jet passed in front of the RC-135, Pentagon spokesman Peter Cook told reporters.
"One of the maneuvers conducted by the Chinese aircraft during this intercept was perceived as unsafe by the RC-135 air crew and at this point, right now, there's no indication this was a near collision, but the report that came back was that the plane operated in an unsafe fashion," Cook said.
The intercept follows a more dangerous maneuver last year
when an armed Chinese fighter jet came within approximately 20 feet of a U.S. Navy P-8 aircraft, at one point rolling to its side to show the U.S. plane its weapons load, Pentagon officials said at the time.
'Pattern of aggressive behavior'
While last week's incident was not seen of as provocative, Cook said the incident was still under review.
It's already rankled some in Washington. Sen. John McCain, the Arizona Republican who chairs the Senate Armed Services Committee, said the "dangerous Chinese intercept of a U.S. aircraft last week shows that China feels emboldened to continue its pattern of aggressive behavior in the Asia-Pacific region."
From Beijing's perspective, the timing of Tuesday's announcement from the Pentagon certainly could have been better. President Xi Jinping is in the United States and will have an official state visit Friday with his American counterpart, Barack Obama.
In a written interview with the Wall Street Journal
, Xi downplayed differences between the two countries, saying "even family members don't always see eye to eye with each other."
As to China possibly flexing its military muscles, the President insisted his country's approach is "defensive in nature."
"In strengthening our defense and military,... we are not going after some kind of military adventure," Xi said. "It never crosses my mind."
U.S. woman held in China since March
Another sensitive issue between the two countries came to light around the start of Xi's trip: the months-long detention of an American woman by Chinese authorities on accusations of spying.
Sandy Phan-Gillis has been in Chinese custody since she was stopped in March during a trade visit she was on with officials from Houston, CNN affiliate KTRK reported
"My wife is not a spy, and she is not a thief," her husband, Jeff Gillis, told the broadcaster. My wife is a hard-working businesswoman."
The U.S. government says it is closely monitoring Phan-Gillis' case.
"We've been to visit her six times since her arrest, and we've raised her case with Chinese government officials on multiple occasions at a very senior level," Mark Toner, a spokesman for the U.S. State Department, said Tuesday at a regular briefing
Chinese Foreign Ministry spokesman Hong Lei told reporters Tuesday that Phan-Gillis is "suspected of endangering China's national security and is currently being investigated by China's relevant authorities."
Gillis said he chose to go public over his wife's detention this week in the hope of getting Obama's attention during Xi's visit.
"I want my wife back and I'm sure that she wants to be back very much too," he told KTRK.