North Korea nuclear fears grow
He convened top security and foreign affairs officials and ordered them to take "substantial and high-profile important state measures," state media have said.
Last week, the council condemned North Korea's launch of a long-range rocket as a violation of a ban against nuclear and missile activity.
The council, including North Korea ally China, punished Pyongyang with more sanctions and ordered the regime to refrain from a nuclear test - or face "significant action".
North Korea responded by rejecting the resolution and maintaining its right to launch a satellite into orbit as part of a peaceful civilian space program.
It also warned that it would keep developing rockets and testing nuclear devices to counter what it sees as US hostility.
North Korea is estimated to have enough weaponised plutonium for four to eight bombs, according to American nuclear scientist Siegfried Hecker, who visited the country's nuclear complex near Pyongyang in 2010.
However, it is not known whether North Korean scientists have found a way to build nuclear warheads small enough to mount on a long-range missile.
Experts say regular tests are needed to perfect the technique, and another atomic test could take the country closer to its goal of building a warhead that can be mounted on a missile designed to strike the US.