Pompeo has maintained that complete, verifiable and irreversible denuclearization is the "only outcome" acceptable to the US and that the Trump administration hopes ultimately to reach an agreement with the North Koreans that it can submit to Congress "so that when administrations do change, as they inevitably do, and this one will ... that Chairman Kim will have comfort that American policy will continue down the same path".
Trump and Kim arrived in Singapore hours apart Sunday.
Kim only started meeting with foreign leaders in recent months, slowly shedding a reputation as the reclusive ruler of the so-called Hermit Kingdom after summits with the Chinese and South Korean presidents.
Trump has said he hopes to make a legacy-defining deal for the North to give up its nuclear weapons, though he has recently sought to minimize expectations, saying more than one meeting may be necessary.
On Sunday, Kim Jong-un arrived in Singapore where he is expected to hold a meeting with US President Donald Trump on June 12.
Donald Trump and Kim Jong-un arrived in Singapore on Sunday ahead of their Tuesday meeting.
Kim Jong Un met Singapore Prime Minister Lee Hsien Loong shortly after his arrival, driving from the St. Regis Hotel where he is staying, through the famous Orchard Road shopping district, which was closed off for his tightly guarded motorcade.
The US president and North Korean leader are staying in separate hotels, not far from each other, and will meet on Tuesday at a hotel on Sentosa, a popular tourist island a few hundred metres off the main island of Singapore. The North Korea side is being led by Vice Foreign Minister Choe Son-hui.
On the streets, Kim and Trump impersonators thrilled around 100 fans who paid $10 to take selfies at Bugis Junction mall at the weekend.
Close US ally Japan has urged Trump to bring up the decades-old issue of its citizens abducted in 1970s and 1980s to train Pyongyang's spies in Japanese language and customs.
The commemorative coin issued ahead of the US-North Korea Summit.
Trump added that he believes Kim, half the age of the American president, "wants to do something great for his people".
Kim's younger sister, Kim Yo-jong, who assisted with the lowering of tensions between North Korea and the global community by attending the Winter Olympics in South Korea, is among the North Korean delegation.
Asked by a reporter how he felt about the summit, Trump said: "Very good".
The US president successfully sought to tighten United Nations sanctions on the North, and to get its traditional ally, China, to go along. However, the South Carolina Republican noted that he is "not here to spread democracy" or to unite the North with South Korea.
Washington is demanding the complete, verifiable and irreversible denuclearistion (CVID) of North Korea.
Likely to attend the summit with Trump are Pompeo, Bolton and White House chief of staff John Kelly.
Tuesday's Singapore meeting is the climax of the astonishing flurry of diplomacy on and around the Korean Peninsula this year, but critics charge that it risks being largely a triumph of style over substance.
North Korea's official newspaper Rodong Sinmun proclaimed Kim's arrival in Singapore on its front page, in unusually swift coverage of his worldwide visit.
"SPUR OF THE MOMENT" Trump, speaking in Canada on Saturday, said any agreement at the summit would be "spur of the moment", underscoring the uncertain outcome of what he called a "mission of peace".
Mr Kim has also said he wants to focus on building the North Korean economy - and thus wants sanctions relief and worldwide investment.