Kim Jong Un warns: I'm ready for war
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The Korean Central News Agency said that Kim called for increasing the isolated communist government's "political and military might" in the new year, according to USA Today.
However, he also expressed a willingness to work toward reconciliation with South Korea.
After touting the "gigantic struggle" and "eye-opening successes" in North Korea in 2015, Kim used his televised address to emphasize work toward "peace on the Korean Peninsula."
"But if invasive outsiders and provocateurs touch us even slightly, we will not be forgiving in the least and sternly answer with a merciless, holy war of justice," Kim added.
The leader has made similar remarks in the past involving the United States. 
In August, Pyongyang said it would retaliate against intensified multinational military exercises in which the U.S. took part.
And Kim reportedly told his troops to prepare for "sacred war" after the exercises in 2012.