The congress, which opened on Friday, has largely been seen as an elaborate coronation for the 33-year-old Kim, securing his status as supreme leader and confirming his legacy "byungjin" doctrine of twin economic and nuclear development.
Yesterday, the thousands of delegates to what is technically North Korea's top decision-making body, adopted a report submitted by Kim the day before to simultaneously push forward economic construction and "boost self-defensive nuclear force both in quality and quantity."
"But if the south Korean authorities opt for a war... We will turn out in the just war to mercilessly wipe out the anti-reunification forces," said the document published by the North's official KCNA news agency.
Reiterating the North's long-held argument that its push for a nuclear deterrent was forced by US hostility, the congress said the nuclear weapons programme would move forward "as long as the imperialists persist in their nuclear threat."
More From This Section
The government in Seoul dismissed his remarks, including a vow to pursue global denuclearisation, as meaningless propaganda.
"There is absolutely no sincerity in talking about the necessity of military talks...While calling oneself a nuclear weapons state and launching nuclear and missile provocations," defence ministry spokesman Moon Sang-Gyun said.
Moon said the party congress had only served to reaffirm North Korea's intention to develop its nuclear arsenal, and added that Seoul would continue to counter those ambitions with sanctions and pressure.
North Korea has carried out four nuclear tests -- two of them under Kim's leadership.
The North said its most recent test in January was of a powerful hydrogen bomb, although experts questioned the claim given the relatively low yield.