Washington remained committed to the "complete, verifiable and irreversible" denuclearisation of North Korea, Pompeo added, after the historic US-North Korea summit in Singapore drew criticism for its vague wording on plans for Pyongyang to give up its nuclear weapons.
"We believe that Kim Jong Un understands the urgency... that we must do this quickly," he said of the effort to have North Korea abandon its atomic arsenal.
Washington's top diplomat was in Seoul to brief his South Korean and Japanese counterparts after President Donald Trump's post-summit comments sparked confusion and concern in Tokyo and Seoul.
But Pompeo insisted at a joint press conference with the two countries' foreign ministers that there was no daylight among the allies on how to achieve the denuclearisation of North Korea.
Contrasting the Trump policy with previous US administrations, Pompeo said: "In the past, they were providing economic and financial relief before... complete denuclearisation had taken place."
"That is not going to happen, President Trump made that clear."
Pompeo's comments came after North Korean state media reported Wednesday that Trump had not only offered to stop military exercises during dialogue, but also lift sanctions imposed on Pyongyang.
Trump said after his meeting with Kim -- the first between sitting US and North Korean leaders -- that Washington would halt its joint military exercises with South Korea, an announcement that caught Seoul -- and apparently the Pentagon -- by surprise.
The US and South Korea conduct several large drills every year to maintain readiness for operations on the peninsula, a source of irritation for Pyongyang, which considers them preparations for an invasion.