North Korean leader Kim Jong Un has warned top ruling party officials of the "grave situation" facing the nuclear-armed state's economy and called for urgent corrective measures.

North Korea on Saturday warned Japanese Prime Minister Shinzo Abe that he could soon see a "real ballistic missile" while excoriating him as the "most stupid man ever known in history".

The colourful condemnation comes two days after the isolated state tested what it called a "super-large multiple launch rocket system", with South Korea reporting that two projectiles came down in the Sea of Japan, also known as the East Sea. 

The possibility of talks between nuclear-armed North Korea and Washington is "narrowing", Pyongyang said Tuesday after the US State Department reaffirmed its designation as a state sponsor of terrorism.

North Korea said Sunday it has "no intention" to continue nuclear talks unless the United States takes steps to end hostilities, a day after negotiations in Sweden broke down.

North Korean and US officials on Saturday were set to resume nuclear talks in Stockholm after months of deadlock and Pyongyang's defiant test of a sea-launched ballistic missile this week.

US aggression and an obsession with disarmament mean another summit between Washington and Pyongyang is looking doubtful, North Korea said on Friday, even as it praised US President Donald Trump as "bold" and "wise".

The right-hand man of Venezuelan President Nicolas Maduro is in North Korea leading a "high-level delegation", state media in the North said Thursday, as both nations grapple with economic pressures from international sanctions.

North Korea on Monday demanded the United States provide security guarantees as a precondition to resuming deadlocked nuclear talks, dampening hopes for progress at a working-level dialogue expected in the coming weeks.

North Korea Saturday lashed out at US Secretary of State Mike Pompeo over his comments on Pyongyang's "rogue behaviour" and warned its expectations for nuclear talks with Washington are "gradually disappearing".

North Korea Saturday fired what appeared to be two short-range ballistic missiles  into the sea after vowing to remain the biggest "threat" to the United States and branding Secretary of State Mike Pompeo as "toxin."