SEOUL, Jan. 7 -- South Korea's presidential office said Thursday that the country will resume propaganda broadcasts from Friday noon with loudspeakers in border areas with the Democratic People's Republic of Korea (DPRK).

Cho Tae-Yong, the first deputy chief of the presidential security office, made the announcement in a press briefing of the planned resumption, which the DPRK had called a"direct act of declaring war."

The South Korean military stopped the broadcasting after the Aug. 25 agreement reached last year between top-level military advisors to South Korean President Park Geun-hye and top DPRK leader Kim Jong Un to defuse tensions on the Korean Peninsula.

The resumption would come after the DPRK announced on Wednesday its first successful test of a "hydrogen bomb." It marked the fourth in total and the second since top leader Kim took power in 2011. The DPRK's previous nuke tests were conducted in 2006, 2009 and 2013, respectively.

Cho said that Pyongyang's fourth nuclear test, which was staged in defiance of repeated warnings from Seoul and the international society, was in direct violation of promises and obligations like UN Security Council resolutions.

The nuclear test was also in a grave violation of the Aug. 25 agreement, Cho said, noting that it was an abnormal situation stipulated in the agreement where the propaganda broadcasts can be resumed under such conditions.

In accordance with the Aug. 25 agreement, the South Korean government decided to resume the broadcasts with loudspeakers in frontline areas from noon on Jan. 8, Cho said.

The South Korean military, which has maintained a full defense posture, will sternly retaliate against any possible DPRK provocations, he added.