North Korea agreeing to discuss denuclearisation “is evidence that President [Donald] Trump’s strategy to isolate the Kim regime is working,” US Vice-President Mike Pence has said.
He said the US had made “zero concessions” and “consistently increased the pressure” on North Korean leader Kim Jong-un.
An unprecedented summit between the two leaders is due to take place by May.
It comes only months after the pair hurled insults at each other.
Mr Trump has hailed the dizzying shift in North Korea’s position as “great progress” but said sanctions would remain in place.
South Korean envoys earlier briefed the US president on the meeting they had this week with Mr Kim, saying he was now “committed to denuclearisation”.
South Korea’s President Moon Jae-in said the news of the Kim-Trump meeting had come “like a miracle”.
“If President Trump and Chairman Kim meet following an inter-Korean summit, complete denuclearisation of the Korean peninsula will be put on the right track in earnest,” he said.