The military belatedly confirmed that one of the North Korean drones that infiltrated South Korea's airspace on December 26 breached a no-fly zone that includes the skies over the South Korean presidential office.

A military official said on Thursday that the inspection of military preparedness by the Joint Chiefs of Staff(JCS) determined that the drone passed through the northern section of the "P-73" no-fly zone.

The P-73 zone covers a radius of three-point-seven kilometers centered on the Ministry of National Defense building and new presidential office, extending to parts of Jung, Seocho and Dongjak Districts.

However, the official denied some media reports that the drone flew 700 meters into the zone or came as close as three kilometers away from the presidential office.

Last Thursday, the JCS denied that the North Korean drone encroached into the P-73 zone after an opposition lawmaker said there was a high possibility that the drones invaded the no-fly zone.