During a parliamentary audit of the presidential office Cheong Wa Dae and its national security office, the main opposition Liberty Korea Party slammed Lim for what it called acting like the president inspecting the zone.

"When the president is abroad, how could the minister and vice minister of defense, the unification minister and the spy chief visit the DMZ en masse?" said Rep. Sung Il-jong of the LKP.

Sung also raised questions about Lim's alleged mishandling of military secrets over the presidential office's release of footage that inadvertently leaked the location of an entrance to a South Korea guard post during Lim's DMZ trip.

The ruling Democratic Party defended Lim, saying that his trip was a necessary part of the government's efforts to bring peace to the Korean Peninsula.

South and North Korea earlier agreed to conduct a joint project to retrieve war remains from the site between April and October next year.

"I don't understand why my visit was problematic. I went there on the committee's judgment that it is the site for the project to retrieve war remains, a key element in the inter-Korean agreement," Lim said.

But he apologized for the release of the footage that failed to blur the location of the guard post. (Yonhap)