A South Korean government researcher on Wednesday floated the idea of using drones, cyberattacks and high-power microwave (HPM) weapons to counter North Korea's nuclear and missile threats.

Speaking at a security forum, Cho Nam-hoon of the state-run Korea Institute for Defense Analyses stressed the need to devise various contingency measures, including building "left-of-launch" capabilities to defeat a North Korean attack even before its launch.

His proposal followed a recent report by a UN panel of experts that Pyongyang has continued to develop its nuclear and ballistic missile programs, despite Seoul's continued push for inter-Korean reconciliation and engagement.

As a contingency scenario for operations in the pre-launch phase, Cho called for using a "drone-based salvo" to attack the entrance of a nuclear weapons tunnel in the North and kinetic energy munitions to cause the tunnel to collapse.

In the boost phase following the launch of a nuclear weapon, the researcher proposed the use of cyberattacks to disrupt or disable its flight and of HPM weapons to destroy its guidance system in the midcourse phase.

Noting the North's plutonium- and uranium-based nuclear weapons programs, Cho estimated that the number of its nuclear warheads could double by around 2040. The North is known to have dozens of nuclear warheads, though estimates vary. (Yonhap)