Seoul has announced it would resume broadcasting propaganda into North Korea in response to Pyongyang's nuclear weapon test. Use of the loudspeakers triggered a military crisis between the two Koreas last year.
South Korea on Thursday said loudspeakers would resume blasting propaganda across the heavily militarized border with the North, a practice that Pyongyang last year threatened to respond to with a military attack.
South Korea's presidency said the North's nuclear test this week violated international law and an August agreement between the two Koreas to ease tensions. The North said the nuclear device was a hydrogen bomb, a claim other governments and experts have questioned.
"Our military is at a state of full readiness, and if North Korea wages provocation, there will be firm punishment," a senior presidential national security official, Cho Tae-yong, said in a statement.
North and South Korea exchanged artillery fire in August over the propaganda broadcasts into the hermit state. Seeking to defuse tensions, the two Koreas struck a deal that saw the South cut the music and propaganda that it had been blaring across the border for two weeks.
Part of the deal stipulated the loudspeakers would remain silent "unless an abnormal case occurs."
North Korea's widely condemned nuclear test - its fourth - presumably counts as an "abnormal" occurrence.
cw/se (AFP, AP, Reuters)