That appeared to be the main issue of debate on Monday as top aides from both sides met for last-minute talks on the joint communique to be issued after the historic summit between the two leaders.
"Substantive and detailed meetings in #Singapore today as Ambassador Kim meets with #DPRK", Pompeo wrote in a Twitter post in which he included a photograph of the meeting between US Ambassador to the Philippines Sung Kim, North Korean Foreign Ministry senior official Choi Sun Hee and other delegates from both countries.
But there are doubts denuclearisation of North Korea is achievable in the short term.
The summit between Kim and Trump will cap a remarkable turnaround in relations between two men who were trading furious insults less than six months ago. How long will it take to figure out whether or not they are serious?
"They are still debating over whether to put [the term] "CVID" in the final draft", the source said.
Trump and Kim are staying in separate hotels in the famous Orchard Road area of Singapore, dotted with high-rise luxury apartment blocks, offices and glittering shopping malls.
Another acronym used in nuclear circles is CVIG, or complete, verifiable, and irreversible guarantee.
The White House and State Department have said little about those talks, though people briefed on them said American negotiators found it difficult to make significant headway with the North Koreans, in part because the White House did not back them up in taking a hard line.
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Discussions would focus on "the issue of building a permanent and durable peace-keeping mechanism on the Korean peninsula, the issue of realising the denuclearisation of the Korean peninsula and other issues of mutual concern", KCNA said.
The KCNA report noted the summit is being held "under the great attention and expectation of the whole world". She led a North Korean delegation to the Winter Olympics in South Korea.
He told reporters he thinks he will know nearly immediately whether a deal can be made, saying: "I will know, just my touch, my feel".
During the lunch, Trump said he thinks "things can work out very nicely" in Tuesday's meeting.
"Chairman Kim thanked Prime Minister Lee for Singapore's hosting of the US-DPRK Summit", the document adds.
Siegfried Hecker, a noted United States nuclear expert, said the immediate CVID of the North was "unimaginable" and "tantamount to a North Korean surrender scenario". It also annoyed Singapore residents by offering to pay Kim's hotel bill. He is turning 72 on June 14.
Kim, up until his recent high-profile summit with South Korea's president on the southern side of their shared border, has usually hunkered down behind his vast propaganda and security services, or made short trips to autocrat-friendly China.
Led by Sung Kim, a longtime State Department diplomat who now serves as the US ambassador to the Philippines, the USA team had held at least five sessions with the Pyongyang delegation over the past two weeks at the demilitarized zone in Korea. But he cautioned that Kim "won't have that opportunity again" if the talks do not go well - describing this opportunity for diplomacy with the United States as a "one-time shot".
When asked how he feels about the summit after landing in Singapore on Sunday afternoon, US President Donald Trump said, "Very good".
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