Nuclear-armed North Korea condemned the United States over its latest sanctions measures, warning Washington's approach could "block the path to denuclearisation on the Korean peninsula forever".
After a rapid diplomatic rapprochement this year that culminated in the Singapore summit in June between North Korean leader Kim Jong Un and US President Donald Trump, progress has stalled in talks on Pyongyang's nuclear arsenal.
In Singapore the two men signed a vaguely-worded statement on denuclearisation, but have since disagreed on what it means.
Now Pyongyang is demanding sanctions relief and condemning US insistence on its nuclear disarmament as "gangster-like", while Washington is pushing to maintain the measures against the North until its "final, fully verified denuclearisation".
Washington last week added three senior North Korean officials to those subject to sanctions over human rights abuses, including Choe Ryong Hae, who has been considered a right-hand man to Kim.
In a statement carried by the official KCNA news agency, the North said Trump had repeatedly expressed his desire to improve relations with Pyongyang, but the US State Department was "bent on bringing the DPRK-US relations back to the status of last year which was marked by exchanges of fire".
DPRK is the acronym for the North's official name.
In recent months high-ranking US politicians including Secretary of State Mike Pompeo had "almost every day slandered the DPRK out of sheer malice", added the Sunday statement by the policy research director of the foreign ministry's Institute for American Studies.
Using sanctions and pressure "to drive us into giving up nuclear weapons" would be the "greatest miscalculation", it added, and would "block the path to denuclearisation on the Korean peninsula forever".
A second summit between Trump and Kim -- who exchanged personal insults and threats of war throughout 2017 -- is expected to be held next year, with the US leader facing criticism over the planned talks since North Korea has taken few concrete steps to abandon its nuclear and ballistic missile programmes.
Pyongyang has long said it needs the weapons to deter a possible US invasion, and has spent decades developing them, at a heavy cost in both resources and the imposition of multiple sets of UN, US, EU and other sanctions.
But yesterday its nuclear assets were conspicuous by their explicit absence from coverage of the seventh anniversary of the death of Kim's father and predecessor Kim Jong Il, on whose watch Pyongyang carried out its first two nuclear tests.