The official added that the presidential office was set to release an official commentary on the issue.

The move comes one day after the South Korean activist group staged a protest rally in front of Seoul train station as a visiting North Korean delegation arrived there following its overnight visit to Gangneung, 240 kilometers east of Seoul, to inspect possible venues for a musical performance before or during the 2018 PyeongChang Winter Olympic Games.

The activists claimed the Feb. 9-25 Olympic Games were turning into a North Korean event that would help it gain global recognition as a nuclear power. They also burned a picture of North Korean leader Kim Jong-un and a North Korean national flag.

Pyongyang reacted with fury, calling them "unpardonable atrocities."

"If these traitors and psychopaths defaming the dignified Korean nation are allowed to go scot-free, the national reconciliation, unity and the building of a reunified powerful country will be delayed so much," the North's Democratic Front for the Reunification of Korea said in a statement carried by the Korean Central News Agency.

North Korea agreed to take part in the Winter Olympic Games following repeated invitations from Seoul.

The two countries have held three rounds of talks to discuss details of North Korea's participation, which marked the resumption of inter-Korean dialogue after more than two years of sheer confrontation. (Yonhap)