Story highlights US B-1 bomber based in Guam was flying to South Korea for training mission

The US does not recognize Beijing's claims to the region's airspace

Washington (CNN) Chinese officials warned a US military aircraft flying near South Korea Sunday, telling its pilots that they were illegally operating in Chinese airspace and ordering the American plane to leave, a US defense official told CNN.

The pilots of the US Air Force B-1B Lancer bomber responded to the Chinese air traffic controllers, saying that they were conducting routine operations in international airspace and did not deviate from their flight path, according to US Pacific Air Forces spokesman Maj. Phil Ventura.

which covers a disputed island chain and overlaps with airspace claimed by Japan and South Korea. The bombers had entered a controversial Chinese Air Defense Identification Zone (ADIZ) in the East China Sea, which covers a disputed island chain and overlaps with airspace claimed by Japan and South Korea.

The ADIZ declaration required airlines flying over the designated waters to first notify Chinese authorities before transiting. The US and Japanese governments do not recognize China's claim on the area.

"Pacific Air Forces ... did not recognize the Chinese Air Defense Identification Zone (ADIZ) when it was announced in November of 2013, and does not recognize it today," Ventura told CNN.

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