China's newly announced air defence identification zone does not target "normal" flights by international airliners, the Foreign Ministry said on Thursday, as Chinese fighter jets patrolled the zone.
Beijing rejected Japan's demand that it scrap the zone, saying Tokyo should invalidate its own zone first.
Foreign Ministry spokesman Qin Gang said China's zone is not aimed at international airliners. "We hope that relevant countries' airlines cooperate, so there is more order and safety for flights."
Civilian flights have been operating safely and normally since China announced the zone, which covers its Diaoyu Islands, on Saturday, Qin said.
China requires aircraft to provide a flight plan and their identification and to maintain two-way radio contact to respond to identification queries from Chinese authorities.
Qin said airlines from many countries and regions have reported their flight plans to the Chinese authorities.
Shen Jinke, spokesman for the PLA air force, said Chinese fighter jets carried out a regular patrol in the zone on Thursday.
Such patrols are for defence purposes and in line with international practice, Shen said.
Defence Ministry spokesman Yang Yujun said at a news conference on Thursday that Tokyo, which asked Beijing to cancel its zone, set up its own air defence zone in 1969.
More than 20 countries, including the United States and Japan, have established such zones.
"If they want China to cancel the zone, then we would ask that Japan first revoke its own zone. Japan consistently blames others and smears the name of other countries but never examines its own conduct," Yang said.