KIM Jong Un wants to rid North Korea of nuclear weapons for the sake of his children, a former US diplomat claims.

Andrew Kim — an ex-CIA man — says he was in the room when the dictator made the comments to US Secretary of State Mike Pompeo, in the capital Pyongyang last year.

He claims Jong Un said: “I don’t want my children to carry the nuclear weapon on their back."

Before he retired from the CIA, Kim established the agency's Korea Mission Center, in April 2017, and accompanied Pompeo - who was then CIA director - to Pyongyang last year.

In their Singapore summit, Kim and Trump pledged to work towards peace between their countries and for the denuclearisation of the Korean peninsula.

But little progress has been made since then but they are expected to hold a summit in Hanoi, Vietnam, on Wednesday.

They are expected to focus on what steps North Korea might take towards denuclearisation, in exchange for what U.S. concession.

The former CIA officer said the North Korean leader expressed a strong desire to improve ties with the United States as a way to build confidence between them, which he said was needed to end the nuclear weapons programme.

The North Korean leader left Pyongyang by train for his visit to Vietnam on Saturday afternoon, Russia's TASS news agency reported on Saturday citing a North Korean diplomatic source.