North Korea is blaming the South for what it calls "arrogant obstructions" that led to the cancellation of what would have been the first high-level talks between the two foes in years.
The negotiations, which were to take place Wednesday in Seoul, were called off at the last minute following a disagreement over the rank of the officials who would head the delegations of each side.
South Korea had wanted the North to send a Worker's Party official who serves as close advisor to North Korean leader Kim Jong Un. When Seoul declined to upgrade the head of its delegation in return, Pyongyang pulled out of the talks, calling the move an insult.
A spokesperson for the North's government said Thursday the matter was "not a simple issue related to the level of the head of the delegation to the talks but a manifestation of (Seoul's) sinister intention" to abort the dialogue.
The official, with the North's Committee for the Peaceful Reunification of Korea, told state media the South Korean move reflected the "height of discourtesy and disrespect," and showed the South's ignorance of Pyongyang's "social system."
Last week, North Korea refused Seoul's proposal for minister-level talks, which the two Koreas have not engaged in since 2007. On the agenda for the proposed talks were the resumption of two stalled joint commercial projects, as well as the reunion of separated Korean families.
On Wednesday, South Korea's unification minister Ryoo Kihl-jae suggested the cancellation is an unfortunate but necessary part of its new relationship with Pyongyang. He said the North must show sincerity if it wants improved relations with Seoul.
The dispute figures to complicate any further warming of relations, which had deteriorated considerably following North Korea's latest nuclear test.
Seoul said Wednesday that North Korea is not answering an inter-governmental hotline that Pyongyang restored last week in an effort to coordinate the negotiations.