American soldiers in South Korea are busy drawing maps of underground military facilities in the neighboring North to deal with threats that the reclusive nation might pose, South Korea's Yonhap News Agency reported Saturday, citing a military journal. The United States Forces Korea (USFK) in Seoul is also running an educational program for senior South Korean and American military officers to exchange information on such facilities to be able to jointly respond to the impending threats, the report added.

Last year, several South Korean military officials joined the "Underground Facility," a program drafted by the U.S. Army in the mid-1990s, and introduced to USFK in 2007, in a move widely seen as an attempt by Seoul to counter the North's military threats.

"There is the need to grasp underground passageways that can be used by the North Korean leadership if emergency situations or war takes place," South Korean Army Maj. Park Sung-man wrote in the journal Joint Chiefs of Staff, Yonhap reported. "We need to find ways to track down and block their escape routes when they flee Pyongyang."

The information for making the maps was reportedly collected from accounts shared by North Korean defectors and other available information.

The move comes amid reports suggesting that North Korea is strengthening its systems to block the surveillance of its underground activities. According to Park, Seoul would require about 500 to 1,000 U.S.-owned Guided Bomb Unit-28, also known as bunker-buster bomb, to eliminate such facilities in the North.

The tensions between the two Koreas heightened in the wake of military drills between the U.S. and South Korea, which have been termed by the North as training programs for "preparations for a war." Pyongyang has slammed the South for holding these drills near the demilitarized zone between the two rival countries. However, these allegations have been denied by both Seoul and Washington. North Korea, on its part, has been testing ballistic missiles over the last few months.