The U.S. appears to be ramping up surveillance of North Korea by apparently dispatching reconnaissance aircraft for two consecutive days following the regime's recent artillery firing drills on a border island in the West Sea. 

According to private aviation tracker Aircraft Spots on Thursday, a U.S. recon aircraft believed to be an E-8C was spotted in skies about ten kilometers above the Korean Peninsula. 

The flight comes a day after the aviation tracker detected what may have been an RC-135V flying over Seoul and surrounding areas.

The E-8C can closely monitor movements of North Korean troops and equipment at an altitude of nine to 12 kilometers. It was reported that two E-8C planes arrived at a U.S. air base in Okinawa, Japan last month. 

The reconnaissance aircraft, which are considered key strategic U.S. military assets, have in the past been deployed to the peninsula when North Korea showed signs of launching mid- to long-range missiles. 

The flights appear indicative of strengthened U.S. surveillance of North Korea following firing drills on Changrin Islet near the de facto inter-Korean maritime border on Nov. 23.

The drills were apparently directed in person by North Korean leader Kim Jong-un.

[Photo : YONHAP News]