North Korea has threatened to take military action unless South Korea stops its loudspeaker broadcasts across the border.

The South Korean government said Thursday that the North made the threat in a message addressed to chief of the National Security Office, Kim Kwan-jin.

The message from secretary of the North’s Workers’ Party Kim Yang-gon was conveyed through the liaison office at the truce village of Panmunjeom at 4:50 p.m., about one hour after the North fired a shell towards the South.

In the message, the North said that the South Korean psychological warfare operations amount to a declaration of war. It then urged the South to suspend the recently reactivated loudspeaker operations while threatening to launch military operations against the South.

The message then added that it is willing to make efforts to find a breakthrough to resolve the current inter-Korean situation and improve relations.

The Seoul government downplayed the message, saying that the North is only trying to gloss over the fact that the current situation is the result of North Korean land mine explosions in the Demilitarized Zone.

The government stressed that it will sternly deal with any provocation by the North.