The moves would break with decades of policy, and could justify the use of nuclear weapons against Seoul in a future war, according to analysts.
Here's Yang Moo-jin, a professor at the University of North Korean Studies.
"Until now, North Korea couldn't use nuclear weapons against South Korea, who share the same ethnic backgrounds. Now that in state-related regulations, North Korea has secured the justification of using nuclear weapons to hostile countries at any time, this has escalated tensions on the Korean peninsula more than ever."
Moo-jin adds it seems as if North Korea is now viewing inter-Korean relations as a sub-concept of North Korea-U.S. relations.
Since the 1950-53 Korean War ended in a stalemate, both nations have had policies that treat each other differently than other countries.
That has included relying on special agencies and ministries for inter-Korean relations rather than their foreign ministries. As well as embracing policies for a future peaceful reunification, usually envisioning a single state with two systems.
But in remarks to a year-end party meeting last week, North Korean leader Kim Jong Un said peaceful reunification is impossible and hinted at changing relations with what he called the "enemy".
"There is an urgent need for us to establish a new stance on the inter-Korean relation and reunification policy. Now we need to admit the reality and clarify the relationship with South Korea."
He also ordered the military to be prepared to pacify and occupy the South in the event of a crisis.
The extent of the organizational changes is unclear.
Some analysts said North Korea's declarations simply reflect the reality of two countries with deep divisions and disparities.
They predict that now the rhetoric more closely reflects the status quo, there is unlikely to be a major shift in the already antagonistic relationship between the two Koreas.
