South Korean soldiers from an artillery unit participate in a military drill near the demilitarised zone separating North Korea from the South, in Paju, north of Seoul March 29, 2013.
South Korean soldiers from an artillery unit participate in a military drill near the demilitarised zone separating North Korea from the South, in Paju, north of Seoul March 29, 2013.Reuters

South Korea on Thursday pledged that it would "Sternly retaliate" against any provocation from North Korea, a day after Pyongyang issued a warning of an "unimaginable holocaust" if South proceeds with the upcoming joint military exercises with the United States.

South Korean Defense Ministry spokesman Kim Min-seok called the latest threat  "self-contradictory" as North Korean leader Kim Jong-un had called for an end to "slander and calumny" in his New Year's address, with a pledge to improve inter-Korean relationship.

"We will sternly retaliate against North Korea if the North carries out military provocations," Kim said in a regular briefing, the South Korean Yonhap News Agency reported.

The comments came a day after North condemned the planned military drills by South Korea and the US that is going to take place late next month. North Korea had also issued a series of threats of nuclear war against its Southern counterpart and the United States last year, as the two allies carried out the Key Resolve and Foal Eagle exercises.

Meanwhile, South Korea and the United States on Wednesday ended a high-profile military session aimed at countering threats from North Korea's nuclear and weapons of mass destruction. About 40 defense and foreign affairs government officials took part in the two-day meeting held at US Pacific Command in Hawaii.

On the same day, North warned the South that the planned military exercises is a "serious military provocation" and that the ties between North and South will go through a dire eventuality if the exercises are held.

"North-South ties will plunge into a deadlock and unimaginable holocaust and disaster will follow should they go ahead with the nuclear war drills and make military provocations," the North's Committee for the Peaceful Reunification of Korea said late Wednesday.

The unification ministry also sent a message to South's committee on Thursday demanding a cancellation of the scheduled drills.

The message posted on a North Korean propaganda website said that South Korea "will be held responsible for all consequence to be entailed by" the military drills.

South Korea's Defense Ministry, however, dismissed the threats on Thursday vowing to "mercilessly and decisively punish" Pyongyang against any provocative action.

"We will conduct Key Resolve and Foal Eagle Exercise as planned. If North Korea actually commits military aggression at the excuse of what is a normal exercise we conduct as preparation for emergencies, our military will mercilessly and decisively punish them," Kim said.

Despite repeated assurance from Washington and Seoul that the exercises are defensive in nature and are not meant to provoke any country, North Korea suspects that they are a rehearsal of a nuclear war against it.