"On orders of Supreme Commander Kim Jong Un, the KPA frontline large combined units entered into a wartime state all at once, fully armed to launch surprise operations, and wound up their preparedness for action," the agency wrote.
On Thursday, North Korea reportedly fired shells at a South Korean military base across the demilitarized zone, to which Seoul responded by firing back dozens of heavy artillery rounds.
"The enemy's provocation bases and anti-DPRK propaganda bases and means for psywar are within the sight of the KPA's multiple rocket launchers and tactical and strategic rocket forces," the statement reads.
Kim Jong Un ordered his front line troops to be brought to full combat readiness following an exchange of fire on the peninsula. The South Korean Ministry of National Defense pledged a "tough" response to escalating tensions.
The first armed clashes between the neighbors in over five years followed South Korea’s resumed broadcasting of military propaganda over the border toward North Korea. It had suspended the practice over a decade earlier.
Pyongyang has given Seoul a 48-hour deadline to turn off its loud speaker systems along the Korean Demilitarized Zone (DMZ) border.