Sanctions on Korea to remain until complete denuclearisation: Pompeo

US Secretary of State Mike Pompeo has said that economic sanctions on North Korea will stay in place until the reclusive nation achieves complete denuclearisation.

"While we are encouraged by the progress of these talks but progress alone does not justify relaxing the sanctions regime," the Bloomberg quoted Pompeo, as saying at a briefing on Sunday in Tokyo after meeting Japanese Foreign Minister Taro Kono and South Korean Foreign Minister Kang Kyung-Wha.

Pompeo's remarks came barely a day after North Korea expressed disappointment over the attitude of US officials on denuclearisation, calling it "regrettable and really disappointing."

In a statement by an unnamed foreign ministry spokesman carried by North's Korean Central News Agency (KCNA), Pyongyang criticised Washington D.C. for "seeking unilateral and forced denuclearisation", Yonhap News Agency reported.

"The US just came out with such unilateral and robber-like denuclearisation demands as CVID (complete, verifiable and irreversible dismantlement), declaration and verification that go against the spirit of the North Korean-US summit meeting," the spokesperson said.

North Korea's statement is apparently not in sync with the US as Pompeo, who was on a two-day visit to North Korea, said that there was progress being made on North Korea's denuclearisation exercise.

He added that "there's still more work to be done" to achieve the process dismantling North Korea's nuclear weapon and ballistic missiles programme.

Calling the talks "very productive", Pompeo told media that he "spent a good time" talking about denuclearisation, the reports said.