South Korea's defense ministry sent the so-called "4D operation" plan, which will be implemented during the US-South Korea joint war games, to the parliamentary defense committee last Thursday, Yonhap said.
The 4D, which stands for Detect, Disrupt, Destroy and Defense, refers to a joint military operation between forces of Seoul and Washington to destroy Pyongyang's nuclear and ballistic missile programs in time of emergency.
The combined forces are pushing to implement the 4D operation for the first time during the joint military exercises code-named Key Resolve and Foal Eagle, believed to kick off in early March, Xinhua reported.
The Key Resolve command post exercise and the Foal Eagle field training exercise have been denounced by the DPRK as a rehearsal for northward invasion.
The submission of the 4D operation plan to the parliament came a day after the DPRK claimed its first successful test of a hydrogen bomb.
The implementation of the 4D operation plan would come earlier than expected as two months passed after the US and South Korea announced the operation plan during their annual defense meeting in November.