He was speaking after talks with his South Korean opposite number Foreign Minister Kang Kyung-wha to coordinate Washington and Seoul's preparations for the historic encounter.
Some experts believe Kim may try to drag out the process to wait out the Trump administration or seek a deal in which he gives away his intercontinental ballistic missiles but retains some of his shorter-range arsenal in return for a reduced US military presence in the South.
North Korean officials announced Saturday they will take the first steps in less than two weeks to dismantle the country's nuclear test site, as they prepare for the historic summit between leaders of the isolated nation and the United States.
When requested to outline what he meant by everlasting, verifiable denuclearization, Pompeo stated, "I am unsure methods to outline it absolutely, it is fairly clear what which means ... how to make sure North Korea does not possess the capability to threaten the world".
It has one foot in the East and one in the West, is ultra-modern, secure and sometimes mocked as being a little tiresome - Singapore was the safe pick for a historic first meeting between the unpredictable leaders of the US and North Korea.
USA officials said their freedom removed the last major obstacle, providing Trump with tangible evidence that his twin-track policy of engagement and "maximum pressure" was working. With help from the USA, those countries recovered from the devastation of conflict.
Pompeo flew to Pyongyang for talks and to recover three released American detainees, and now a summit date has been set for June 12 in Singapore. "We had good conversations about the histories of our two nations, the challenges that we've had between us", he said.
"We'll require a robust verification program, one that we would undertake with partners around the world which would achieve that outcome", he warned.
She said the US troop presence in the South for the past 65 years plays a "crucial role for deterrence", peace and stability on the Korean peninsula. During his visit, Pompeo finalized the details for the upcoming summit between Trump and Kim.
"There's a danger here of the peace track moving more quickly than the denuclearization track", warned Abraham Denmark, an Asia expert and former senior United States defense official.
In a joint news conference with South Korea's top diplomat, he offered a glimpse of what U.S. "North Korea, you can't tell the difference between North Korea and the Yellow Sea on the west". To the USA, that means the North giving up the nuclear weapons it has already built. Of the three, Kim Dong Chul had been held the longest.