Lawmakers of South Korea's ruling and opposition parties were split over the consequence of the U.S.' move to impose sanctions on North Korean leader Kim Jong-un over human rights abuses earlier this week, local political observers said Friday.

On Wednesday, Washington imposed sanctions on 15 officials and eight agencies on charges of engaging in human rights abuses.

It was the first time the U.S. has imposed direct sanctions on the North's leader and the designation also marked the first-ever U.S. sanctions on Pyongyang over its human rights abuses.

"Kim Jong-un has executed more than a hundred high-ranking officials since killing (his uncle) Jang Song-thaek," Rep. Ha Tae-Keung of the ruling Saenuri Party said, adding Kim can be considered a serial killer.

"The decision implies that Kim is considered an individual criminal, and thus can be physically eliminated," Ha added.

"(Following the move), South Korea should join the U.S. sanction against the North, and hold watchful eyes on Kim's whereabouts around the clock," Ha also said. "The budget on Pyongyang-related divisions under the National Intelligence Agency should also be increased by tenfold."

Rep. Woo Sang-ho, the floor leader of the Minjoo Party of Korea, however, expressed reservations about Washington's decision.

"One should be careful about imposing sanctions and pressure that may hurt the peace and safety of the Korean Peninsula," Woo said. "We know the move is aimed at Pyongyang's human rights issues, but it may lead to unnecessary tension between the two Koreas and Northeast Asia."

The party whip added Kim should not be considered the same as Muammar Gaddafi, a Libyan dictator whose regime collapsed in 2011.

The U.S. had earlier slapped Gaddafi with an individual sanction. (Yonhap)