In what was termed as an "unprofessional" move, two Chinese Sukhoi Su-30 jets intercepted the US Air Force's radiation detection plane flying over the East China Sea on Wednesday (17 May). "The US is concerned over China's clear statement that it is its region and it controls it", the military analyst told Sputnik.
The latest incident was the second bit of trouble this year involving a Chinese aircraft and a USA plane.
She said the issue was "being addressed with China through appropriate diplomatic and military channels", and a military investigation was under way.
Mid-air interceptions occur routinely in worldwide airspace, but the USA military will often call out foreign pilots if it judges the maneuvers to be risky or unprofessional.
The US sniffer aircraft has previously been used to detect evidence of possible nuclear tests by North Korea.
"But as we said before, for a long time, the surveillance activities of USA military planes and ships near China's territory are very likely to lead to misunderstanding, miscalculation, and accidents on the sea or in the air", she told a regular news conference.
In that incident, the two planes flew within 1,000 feet (300 meters) of each other in the area of the contested Scarborough Shoal, just 230 km (140 miles) from the Philippine coast, media reports said. At that time the USA called the incident unsafe.
Such incidents have occurred occasionally over and within the South China Sea, which China claims virtually in its entirety.
"For a long time USA ships and aircraft have been carrying out close up surveillance of China which can really easily cause misunderstandings or misjudgments or cause unexpected incidents at sea or in the air", she told the Reuters news agency.
"This is escalating the situation and absolutely unacceptable", Defense Minister Tomomi Inada told a news conference on Friday, referring to the incursion and drone flight.