Trump responded to the provocations with provocative rhetoric, belittling Kim as "Little Rocket Man" and threatening "fire and fury".
Trump, who is offering to reduce economic sanctions on North Korea in exchange for denuclearisation, also seemed to warn Kim that the summit is a "one-time opportunity" that should not be wasted. It will certainly be an exciting day and I know that Kim Jong-un will work very hard to do something that has rarely been done before ...
The understated photo op belied the intensive behind-the-scenes negotiations that continued between the USA and North Korean delegations less than 24 hours before Trump was scheduled to meet Kim at the Capella Hotel on the resort island of Sentosa, just off Singapore's southern coast.
"I am on a mission of peace and we're going to be carrying the hearts of millions of people from all", he said.
In the lead up to the summit, North Korea rejected any unilateral nuclear disarmament, and KCNA's reference to denuclearization of the peninsula has historically meant that Pyongyang wants the United States to remove its "nuclear umbrella" protecting South Korea and Japan.
Trump told Lee that he has a "very interesting meeting" tomorrow which he said is "going to work out very nicely". That's what I do. "Given the history of the way KCNA has reported, I think that is a sign for optimism".
The meeting was Trump's only scheduled public event as White House officials prepared for the critical meeting on Tuesday with Kim. Kim also released a statement in September that said he will "surely and definitely tame the mentally deranged USA dotard with fire". An invitation to visit Trump in October, coupled with a few interactions with the UN General Assembly could be most catalytic.
But after a cooling of the rhetoric, both sides began forging tentative contacts that eventually saw Mike Pompeo - the former head of the Central Intelligence Agency who is now secretary of state - meet Kim in Pyongyang.
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"Our people have been working very, very well with the representatives of North Korea".
The tone heading into the meetings is positive, but the risk that things will go awry is also very real.
A Trump administration official, speaking on condition of anonymity, said the US side was entering the talks with a sense of optimism and an equal dose of scepticism given North Korea's long history of developing nuclear weapons.
The talks come after a year of surging tensions between the two nuclear-armed rivals that saw Kim ramp up the development of his weapons programs as the two leaders traded a series of pointed personal barbs - as well as threats of war - at one another.
"Even the Agreed Framework, we knew it failed in 2002 for sure, but for a long time we thought it was successful", Terry said. "It will be a process".
"North Korea can not denuclearise completely right now and hope to be safe from a president who said we're going to rain fire and fury on you, from a country that's been calling you evil for 25 years", said Horacio Falcao, a negotiations expert at the INSEAD graduate business school in Singapore.
Pyongyang has said it is willing to deal away its entire nuclear arsenal if the United States provides it with reliable security assurances and other benefits. Kim is, essentially, upsetting two decades of carefully choreographed North Korean statecraft and stepping into the unknown.