South Korea and the United States are jointly conducting a pilot search and rescue drill which will continue for 12 days until March 29th.
The drill, which began on Monday, is an Air Force exercise to train for rescuing stranded pilots.
The E-3 early warning and control aircraft owned by U.S. forces in Japan is also known to have made a flight to the Korean Peninsula.
A South Korean military source said the aircraft will return to Kadena Air Base in Okinawa after taking part in the drill.
The joint rescue drill is regularly held twice a year in the first and second half of the year.