Kim Jong Un instructed North Korean troops to "wipe out South Korea" in the latest sign of aggression from North Korea's supreme leader. Kim's remarks came during a military border exercise this week as the United Nations Security Council adopted sanctions targeting Pyongyang's coal exports.

"This is how we must forcefully respond to those South Koreans. At first strike we must completely break the will of those South Koreans and wipe them all out," Kim said according state-controlled television network KCTV.

Kim spoke directly to a marine brigade and a frontline unit that has been tasked with fighting Seoul. The drills included the rapid firing of artillery and Kim was briefed on their training plan, UPI reported Friday.

The annual winter training exercise was held near a disputed maritime border in the Yellow Sea. North Korea state media said an island targeted during the training saw loud explosions and light that simulated "the enemy's cities and military targets submerged in a sea of fire."

The South Korean island of Yeonpyeong, which North Korea attacked in 2010, killing four South Koreans, sits near the disputed border. Pyongyang warned of another "brutal baptism of fire" in November.

South Korea hasn't taken Kim's threats lightly, especially after Pyongyang claimed earlier this year it had carried out a successful test of a nuclear warhead and tested a high powered rocket engine that could be used for an intercontinental ballistic missile. In September, South Korea's defense minister revealed it has a plan to assassinate Kim if necessary. 

"Yes, we do have such a plan," Han Min-koo said during a parliamentary meeting. "If it becomes clear the enemy is moving to attack the South with nuclear missile, in order to suppress its aims, the concept [of the special forces] is to destroy key figures and areas [that] include the North Korean leadership." 

The U.N. Security Council unanimously adopted a resolution Wednesday imposing new sanctions against North Korea's exports of coal, its biggest export.