North Korea has accused the US of using "gangster-like" tactics to push it towards nuclear disarmament after a fresh round of high-level talks.
It branded the US attitude at the meeting as "extremely troubling".
The statement, by an unnamed foreign ministry official, gave a starkly different account from one provided by US Secretary of State Mike Pompeo just hours before.
He had said progress was made during his two-day visit to Pyongyang.
It is the first time he has visited North Korea since a summit between Donald Trump and Kim Jong-un in Singapore.
The leader's meeting ended with a promise from Mr Kim to work towards denuclearisation, but details on how this will be achieved remain thin.
A key aim of Mr Pompeo during his visit was to firm up North Korea's commitment to disarmament.
But the North Korean statement, carried by the official KCNA news agency, said the US had gone against the spirit of the summit by putting unilateral pressure on the country to abandon its nuclear weapons.
"We had anticipated the US side would come with a constructive idea, thinking we would take something in return," the North Korean statement said, warning its "resolve for denuclearisation... may falter".
"The US is fatally mistaken if it went to the extent of regarding that [North Korea] would be compelled to accept, out of its patience, demands reflecting its gangster-like mindset," it added.