The US special envoy for North Korea will meet with his North Korean counterpart on Wednesday in Pyongyang to prepare for a summit later this month between President Donald Trump and North Korean leader Kim Jong-un, the US State Department said on Monday.

US envoy Stephen Biegun said last week he aimed in working-level negotiations with his new North Korean counterpart Kim Hyok Chol to map out "a set of concrete deliverables" for the second summit between Trump and Kim Jong-un.

Biegun said he would be aiming for "a roadmap of negotiations and declarations going forward, and a shared understanding of the desired outcomes of our joint efforts."

An unprecedented first summit between Trump and Kim Jong-un last June in Singapore yielded a vague commitment by Kim to work toward the denuclearisation of the Korean peninsula, where US troops have been stationed since the 1950-53 Korean War.

In the US view, Pyongyang has yet to take concrete steps to give up a nuclear weapons program that threatens the United States, while North Korea has complained that Washington has done little to reciprocate its freezing of nuclear and missile testing and dismantling of some nuclear facilities.

On the same day the US government confirmed the fresh talks, UN monitors said North Korea is working to ensure its nuclear and ballistic missile capabilities cannot be destroyed by military strikes.