The next-generation fighter jet F-15K on Monday flew over the nation's easternmost islets of Dokdo to check air defenses.

Air Force Chief of Staff Kim Seong-il and wing commander Lee Yeong-su flew the Slam Eagle and circled around the islets for seven minutes after taking off from Daegu.

The jet returned to the Daegu airfield after passing over Ulleung Island and Goseong, Gangwon Province, on its way back.

An air force official said the fighter jet can fly from Daegu to Dokdo in eight minutes at supersonic speed, but the flight Monday was done at a cruising speed of 800 kilometers an hour because flight regulations forbid hypersonic flights in peace time.