Kim, the eldest son of late North Korean strongman Kim Jong-il, was killed in an airport in the Malaysian capital of Kuala Lumpur on Feb. 13 after being attacked by two women who are suspected to have used some unidentified poison.

"If we put together the announcement by Malaysian authorities and various pieces of information and circumstances, it appears that the North Korean regime is behind this incident," Hwang said.

"This clearly demonstrates the reckless and brutal nature of the North Korean regime that uses whatever means possible to stay in power," he added.

On Sunday, Malaysian police announced all five male suspects in Kim's murder were North Korean, with four of them having already returned to Pyongyang -- an announcement that further reinforced arguments that Kim was assassinated by the communist state's operatives.

The acting president also urged top officials to stay alert for the possibility that Pyongyang could mount terrorist attacks on South Korean officials and citizens.

"We should also thoroughly prepare against the possibility of the North's other provocations that could be staged to deflect international attention (from the murder of Kim)," Hwang said, stressing the need to maintain a robust readiness posture under the South Korea-US alliance.

Hwang, in addition, instructed the military to ensure a strong deterrent against the North's provocations through the allies' annual military drills slated to begin next month.

The NSC session was attended by top security and diplomatic officials, including the ministers of defense, foreign affairs and unification; the National Intelligence Service chief; and the senior presidential secretary for foreign affairs and security. (Yonhap)