Korea's top security officials discussed expanding its air defence zone on Sunday amid international disputes kindled by China's new airspace policy, the presidential office said.
National Security Office chief Kim Jang-soo convened the top security policy meeting after President Park Geun-hye recently directed her security staff to explore ways to protect national interests including the expansion of the country's air zone.
Beijing on Thursday rejected Seoul's demand that it adjust its newly drawn Air Defence Identification Zone, which overlaps with those of South Korea and China.
Related ministers discussed the airspace issue and the dispatching of troops in aid to the Philippines at the top security policy coordination meeting, senior presidential press secretary Lee Jung-hyun told reporters.
The Seoul government is said to be considering areas including the country's southernmost island of Marado; Hongdo Island, an uninhabited island south of Geojedo Island; and Ieodo, a submerged rock within the overlapping exclusive economic zones of South Korea and China.
Set up in 1951 by the US Air Force to block communist forces, South Korea's ADIZ does not cover the country's airspace over some of remote spots.
The outcome of the top security meeting, which was withheld from the media, is expected to be finalized after policy coordination with the ruling Saenuri Party on Tuesday, officials said.
Meanwhile, the Ministry of Land, Infrastructure and Transport said that civilian aircraft flying China's new air defence zone should not submit its flight plans to China, as Seoul does not recognise the unilateral zone.