The new South Korean air zone announced on Sunday includes airspace over two disputed islands to its south and the Seoul-controlled reef of Ieodo, which China calls Suyan and also claims as its own.

The reef is also covered by Beijing's new air defense zone, which it announced on November 23.

The South Korean Defense Ministry insisted that the expansion would not infringe on neighboring countries' sovereignty.

The Defense Ministry said the new air defense and identification zone was designed to have its southern boundary coincide with its flight information region for civil aviation. It said it had fully explained its position to related countries.

It said the zone would take effect on December 15.

The Chinese Air Defense Identification Zone (ADIZ) that was declared unilaterally last month in the East China Sea also takes in Japanese-controlled islands whose ownership is a source of contention between Tokyo and Beijing.

Beijing has asked foreign planes flying through the zone to identify themselves. The United States, Japan and South Korea have all refused to recognize the new zone and have sent military flights through it, so far without incident.

tj/rc (AFP, dpa, Reuters)