North Korea's military said on Tuesday it is reviewing a plan to reenter zones that had been demilitarized under an inter-Korean agreement and "turn the front line into a fortress."

The General Staff of the Korean People's Army(KPA) said in a statement that it is keeping a close watch on the current situation in which inter-Korean relations are turning worse. 

In a statement carried by the Korean Central News Agency, the KPA said the army is studying a plan to advance into zones that had been demilitarized under the inter-Korean agreement. This includes turning “the front line into a fortress” and further heightening military vigilance against the South.

North Korea did not elaborate on which demilitarized zones, but seems to be referring to regions in the western border town of Gaeseong and Mt. Geumgang on the east coast.  
 
The KPA also unveiled a plan to send its own propaganda leaflets into South Korea, saying it is considering opening front-line areas and waters off the southwest coast to cooperate in a large-scale campaign against the enemy.   

The KPA said as the Central Military Commission of the Workers' Party called for those action plans, the army will map out the plans and secure approval from the commission. It added that it will rapidly and thoroughly implement any decisions and orders from the party and government.