Trump has said his aim is to get rid of the North's nuclear weapons, and Kim has repeatedly expressed a commitment to denuclearization, although it's unclear on what terms.

Pompeo said the US has no interest in following a step-by-step process, which, under past administrations, failed to end the North's nuclear ambitions.

"We're not going to relieve sanctions until such time as we achieved our objectives," he said. "We are not going to do this in small increments, where the world is essentially coerced into relieving economic pressure. That won't lead to the outcome that I know Kim Jong-un wants and I know President Trump is demanding."

Pompeo said he hopes to establish a "set of conditions" that will give North Korea an opportunity to have a "historic, big change" in its security relationship with the US, and achieve the US goal of a complete, verifiable and irreversible denuclearization of North Korea.

"We think there's enough that's been discussed that it's important for me to sit with senior North Korean leaders and try and make a big move towards making sure we're prepared for the summit," the top American diplomat said, adding that he's unsure whether he will meet with Kim.

The Trump-Kim meeting has heightened expectations for the release of three American detainees in the North.

"We have been asking for the release of these detainees ... for 17 months," Pompeo said. "We'll talk about it again today. I think it'd be a great gesture if they would choose to do so." (Yonhap)