BEIJING - China "monitored" US B-52 bomber flights in its newly-declared air defence identification zone, the defence ministry said Wednesday, in an assertion of its authority that avoided threatening direct action.
The flight of the giant long-range Stratofortress planes was a clear warning that Washington would push back against what it considers an aggressive stance by Beijing in the region.
Beijing's non-confrontational response elicited scorn from some Chinese netizens as weak in the face of defiance, but analysts said it may never have intended to impose the zone by force.
The Air Defence Identification Zone (ADIZ) in the East China Sea includes Japan-administered islands at the heart of a tense dispute between the two neighbours.
Beijing's controversial demand that aircraft submit flight plans when traversing it triggered a storm of diplomatic protest, and the Pentagon said the B-52s did not comply with the Chinese rules.
But in a statement, Beijing's defence ministry spokesman Geng Yansheng said: "The Chinese military monitored the entire process, carried out identification in a timely manner, and ascertained the type of US aircraft.
"China is capable of exercising effective control over this airspace."
The statement, China's first official response to the US action, did not include any expression of regret or anger at the flight, and appeared to be relatively mild, while reiterating Beijing's claim of control.
Under the rules declared by China, aircraft are instructed to provide a flight plan, clearly mark their nationality and maintain two-way radio communication so they can respond to identification queries from Chinese authorities.
Any that do not comply can face "defensive emergency measures", says Beijing, which portrays the zone as in line with international practice.