Stephen Biegun says he wants to make progress on the commitment from the Kim-Trump summit last June.
The US envoy for North Korea is to hold talks in Pyongyang on Wednesday ahead of a planned second leadership summit between Donald Trump and Kim Jong-un.
Stephen Biegun says he is aiming to establish a roadmap for denuclearisation with North Korea.
A meeting is expected later this month, with Vietnam seen as a likely venue.
But Mr Biegun’s visit comes as a UN report warns North Korea is committing “massive” breaches of sanctions and continuing its weapons programme.
US President Trump and Mr Kim met in Singapore in June, an event which generated significant coverage and optimism, but delivered very few concrete developments.
Both sides said they were committed to denuclearisation, but with no details of how this would be carried out or verified.
Experts caution that despite Mr Trump’s declaration that North Korea is no longer a nuclear threat, the country has never said it would give up its nuclear weapons programme without similar concessions from the US. Sanctions pressure
Mr Biegun is travelling to Pyongyang after holding talks with officials in South Korea, and has said he wants to achieve some “concrete deliverables”.
The US state department has said his visit will “advance further progress on the commitments the president and Chairman Kim made in Singapore”.
The US wants North Korea to make a full declaration of all its nuclear weapons facilities and commit to destroying them, under international supervision – something North Korea has never said it will do.
