BEIJING -- China on Wednesday asserted its right to control a newly designated air defence identification zone, but appeared to play down the impact of an incursion by two U.S. B-52 bombers.
Defence Ministry spokesman Geng Yansheng said China had monitored the U.S. flight late Tuesday over the eastern edge of the zone.
"The Chinese military conducted surveillance during the whole course, identified and ascertained the type of the US jets in time," Geng said.
"China has the ability to take efficient control of the relevant air space," he said.
Foreign Ministry spokesman Qin Gang deferred to the military, adding that China hoped to improve communication with other nations to "jointly maintain flight security."
China's reaction to any similar flights across the zone will be "in accordance with different situations and level of threat," Qin said.
Gary Li, a senior analyst at US-based consultancy IHS Maritime, said the flight of the B-52s was "likely a sign that Washington is displeased with the Chinese ADIZ."
"However, I don't think it is a major intrusion, at least from the Chinese perspective," Li told dpa.
An ADIZ is a control zone rather than a no-fly zone. Announced on Saturday, China's first such zone covers the Japanese-controlled Senkaku islands, a group near oil and gas reserves and claimed by China as the Diaoyu and Taiwan as the Tiaoyutai.
South Korean Foreign Minister Yun Byung-se on Wednesday said the Chinese zone, which overlaps a Japanese zone, "has made already tricky regional situations even more difficult to deal with," Yonhap news agency reported.
The Pentagon said the two B-52s flew "a routine, planned training mission" from a U.S. base in Guam, and did not identify themselves to Chinese authorities as demanded.
Cheng Xiaohe, an international relations expert at People's University in Beijing, said the US flight represented "a small upgrade on the dispute" over the zone.
Although China did not send planes to shadow the U.S. ones, it could do so next time, Cheng said.
"If such a situation happens frequently, it will certainly cause a tense situation," he said of the U.S. flight.
China and the United States are likely to discuss the zone during U.S. Vice President Joe Biden's visit next week, Cheng said.
Gordon Chang, a U.S.-based China analyst, said Washington appeared to be trying to deflect China's anger away from Japan.
"Obviously, the Chinese were not going to interfere with the U.S. Air Force, and they in fact did not," Chang said. "If the Japanese, however, were the first ones to challenge the Chinese zone, Beijing might have provoked an incident.
"The risk of conflict has been reduced, at least for now," Chang said.
Japanese media on Wednesday said the country's two main airlines, JAL and ANA, had stopped reporting details of their flights over the zone to Chinese authorities.
In a separate statement, Qin expressed "strong dissatisfaction" with criticism of the zone by Australian officials.
"The Australian side's irresponsible remarks are completely wrong and the Chinese side cannot accept them," he said.