All evidence showed that the North was behind the assassination, including the use of the nerve agent VX, a banned chemical weapon. Eight North Koreans were named as suspects in the case, though Pyongyang has denied any involvement.

Joseph DeThomas, a former senior State Department diplomat who served as ambassador to Estonia, said in an article carried by 38 North, a website specializing on North Korea analysis, that the US should take stock of the situation before taking action.

"Re-designation offers only limited gains," DeThomas said, adding that the sanctions supposed to come with the designation would add little to the already heavy set of sanctions imposed on Pyongyang for its nuclear and missile programs.

He said that the greatest practical impact Kim's assassination brought about is the deterioration of the North's relations with Malaysia. The Southeast Asian nation, which had taken a relatively restrained approach to inspecting suspect North Korean cargo, is likely to be much more willing to crack down, he said.

"Strategically, there should be no rush to designate Pyongyang. In the larger regional context, the North Korean issue does not need any additional ignition points. Tensions are already running high on the North Korean missile front," DeThomas said.

A decision on designating North Korea needs to be made in that larger context and not as an emotional reaction, the former diplomat said, expressing concern that the situation is already sliding towards confrontation in the region.

"The situation is rapidly taking on the features of a crisis without exit in which all players are taking steps that, while sensible from their own perspective, successively drive each party in turn to adopt more confrontational responses," he said.

Designating North Korea is a card that should be played only if and when it opens up avenues to resolve the larger strategic issue of preventing a North Korean strategic nuclear force from becoming a threat to peace and doing so without provoking a second Korean War, he said.

"The US and its allies should take more time to sort out their own policies and administrations, to put their diplomatic and military ducks in a row for what promises to be a dangerous year on the Korean Peninsula, and to allow the facts on the Kim Jong Nam assassination to emerge," he said. (Yonhap)