North Korea has told South Korea to stop “nonsensical” talk about denuclearisation.
It comes as the North has vowed to keep expanding its military capability.
Kwon Jong Gun, Director-General of the Foreign Ministry’s US affairs department, was responding to claims the South will continue efforts to revive inter-Korean relations and Pyongyang's nuclear negotiations with Washington.
He added the North "will continue to build up" its forces in light of "persistent threats" from the United States.
Seoul had lobbied hard to set up three nuclear summits between North Korean leader Kim Jong Un and President Donald Trump since 2018.
Talks have since stalled, with peace agreements between North and South Korea also under threat in the last week.
The North announced it would cut all government and military communication channels with the South after it failed to stop activists floating anti-Pyongyang leaflets across the border.
Mr Kwon said it was “preposterous to hear the balderdash of [South Korean] authorities, who do not have either any qualification to discuss, or the position to poke their noses into” matters between North Korea and the US.
A separate North Korean statement on Friday said confidence in the South’s government was completely “shattered” and that “regretful and painful times” were ahead for its rival.
“I want to make it clear that we will continue to build up our force in order to overpower the persistent threats from the United States, and such efforts of ours are in fact continuing at this point of time,” Mr Kwon said, dismissing South Korea’s role as a mediator between Washington and Pyongyang in a statement carried by Korean Central News Agency.
Kim Jong-Un's sister has now threatened military action against the South and said Seoul will soon witness the collapse of a “useless” inter-Korean liaison office on the countries' border.
A second summit between the US and North Korea faltered last February, after the latter was denied sanctions relied in exchange for a partial surrender of its nuclear capabilities.
The countries have since failed to agree on another meeting, despite a landmark meeting on the Korean border last June.
Cover Image: North Korean leader Kim Jong-Un oversees military training in 2019 (Picture: KCNA via PA).