"The American people are counting on us to get this right", Pompeo said in his opening remarks for a House Foreign Affairs Committee hearing.
President Trump said the United States would know next week if a summit would take place.
President Trump waves after speaking to reporters on the South Lawn of the White House in Wednesday.
Singapore's United Nations ambassador, Burhan Gafoor, asked the Security Council committee monitoring sanctions against North Korea for a sanctions exemption for the delegation to attend the scheduled June 12 meeting as well as for "preparatory work for the summit".
But there has been increasing pessimism about the meeting after North Korea scrapped the inter-Korean talks and threatened to do the same for the Kim-Trump summit in protest of the South Korea-U.S. military drills and what it calls Washington's push for "one-sided" disarmament.
If it goes ahead, it will be first meeting between a USA and a North Korean leader during more than six decades of hostility, and it would come just months after the North's rapid progress toward attaining a nuclear-tipped missile that could strike America fueled fears of war. Libya's longtime autocratic leader Moammar Gadhafi was killed several years later after a Western-backed military intervention.
North Korea has insisted it won't give up its nuclear weapons program without major concessions from the U.S. Presenting the latest formulation of U.S. policy, Pompeo told the House panel, "Our posture will not change until we see credible steps taken toward the complete, verifiable and irreversible denuclearization of the Korean peninsula. And if we go, I think it will be a great thing for North Korea".
US surgeon general gives aid on plane
The vice admiral, an anesthesiologist, was traveling to MS for a panel discussion on opioid abuse, ABC News reported. Public Health Service Commissioned Corps, a group of more than 6,700 uniformed officer public health professionals.
The group includes an Associated Press Television crew.
Earlier Wednesday, Secretary of State Mike Pompeo told lawmakers the talks were "still scheduled for June 12".
"That model would take place if we don't make a deal, most likely".
"That decision will ultimately be up to Chairman Kim", he said.
Many observers had argued before Mr Trump met Mr Moon that there was too much at stake for Washington and Pyongyang not to proceed with the Singapore summit.
Trump agreed in March to meet with Kim in response to an invitation relayed by South Korea, without first consulting his advisers or running through possible outcomes.
The summit would offer a historic chance for peace between adversaries technically at war since the Korean War ended in 1953 without a peace treaty. But there also is the risk of a diplomatic failure that would allow the North to revive and advance its nuclear weapons program. "North Korea summit", Yoon said, quoting remarks Moon made during discussions with Trump.