North Korea has insisted it will not give in to the US on nuclear disarmament as it contradicted Donald Trump’s account of why his summit with Kim Jong Un failed.
Foreign minister Ri Yong Ho said leader Mr Kim demanded only some sanctions were lifted in exchange for shutting its main nuclear complex.
His comments came during an abruptly scheduled news conference in Hanoi, Vietnam, and were at complete odds with what Mr Trump told reporters hours earlier.
The president had said Mr Kim asked for the removal of all sanctions in exchange for closing the Yongbyon nuclear facility where North Korea enriches uranium.
But Mr Ri said if the US partially removed sanctions they could permanently dismantle all nuclear material production, including plutonium and uranium under US observation.
He added: “This is the biggest denuclearisation step we can take based on the current level of trust between the two countries.”
Mr Ri said Mr Kim had also been ready to offer in writing a permanent halt to the country’s nuclear and intercontinental ballistic missile tests and that Washington wasted an opportunity that “may not come again”.
He said Pyongyang’s position would not change even if the United States offers to resume another round of dialogue.
Mr Trump said two days of talks in the Vietnamese capital had made good progress in building relations and on the main issue of denuclearisation, but it was important not to rush into a bad deal.
“It was all about the sanctions,” the president told a news conference afterwards.
“Basically, they wanted the sanctions lifted in their entirety, and we couldn’t do that.
“We spent all day with Kim Jong Un, he’s quite a guy, quite a character, but we decided not to sign anything.
“It was very productive, but sometimes you have to walk and this was just one of those times,” he said, adding: “It was a friendly walk.”
The White House said both sides would look forward to future talks, though it is not clear when they will take place.
The US president said: “We know what some of the challenges are, but we can ultimately achieve what the world wants, which is to denuclearise North Korea.
“But I’m optimistic about the progress that we made.
“We felt good about the progress but we couldn’t quite get over the line. I hope we will do so in the weeks ahead.”
Mr Trump said the relationship with Mr Kim remained warm, but did not commit to a third meeting with his North Korean counterpart.
He said a possible third summit “may not be for a long time”.
The failure to come to an agreement will raise questions in North and South Korea as well as the US.
Although many sanctions against North Korea are US-led, they involve other nations and the UN, and so any decisions cannot be taken by Mr Trump alone.
Mr Trump hinted at this, saying he could not lose the trust of countries like China if he removed sanctions.