In fact, only hours before the White House announcement, US Secretary of State Mike Pompeo had seemed to lower expectations for the meeting, which Trump had earlier predicted could potentially yield an on-the-spot deal to end the Korean War.
Arriving at the Prime Minister's office after 1900 local time, Kim shook hands with Lee and his staff then sat down to begin talks in front of the cameras before the press was ushered out a few minutes later.
It's a measure of Kim Jong Un's confidence as North Korean leader that he's left his country to meet US President Donald Trump in Singapore, the farthest he's traveled since taking on his father's role in 2011.
Trump and others in his government have said advancement has been made on obtaining a commitment from Kim to give up all his nuclear weapons and long-range ballistic missiles.
Pompeo also said Tuesday's meeting presents a test of Kim's willingness to agree to deal his nuclear weapons away for "protections" from the United States.
He said that was because North Korea was likely to have configured its nuclear forces to permit rapid authorisation to launch in order to offset the risk of a first strike from the United States.
Kim Jong Un enjoys night-time stroll in Singapore ahead of historic summit
Mr Trump's first year in office was marked by bitter exchanges between himself and Mr Kim - as North Korea conducted several ballistic missile tests in defiance of the worldwide community. Forging a peace treaty involving South Korea may be another topic of the Trump-Kim meeting.
Kim told Lee: "The entire world is watching the historic summit between the DPRK and the United States of America, and thanks to your honest efforts. we were able to complete the preparation for the historic summit".
Kim arrived Sunday at the St. Regis hotel, where his close aide has been based as he leads a North Korean advance team arranging security and logistics details.
Kim has shown surprising diplomatic skills in his meetings with overseas leaders this year. "North Korea's nuclear command, control, communications and intelligence is configured to promote a high degree of centralisation in Kim's decision-making, it beggars belief that Kim would not be within secure reach to authorise a possible launch if required", O'Neil added.
Dismantling a secret nuclear arsenal built up over decades would take several years and be extremely hard to check, they say. In my meetings with North Korea's foreign ministry, its officials have repeatedly emphasized that only a leader-to-leader dialogue could break the nuclear impasse.
He also shared a photo of himself and Trump and told the entire world that he's "honored" to call the president a friend.
The insult, equivalent to calling Trump an "old lunatic", was a response to Washington's threat to "totally destroy" North Korea and came at the height of the war of words between the two foes. He wouldn't say whether Trump would consider withdrawing US troops from the Korean Peninsula, but insisted USA sanctions on the North would remain in place until the North denuclearizes.