Both leaders have arrived in Singapore in preparation for their much anticipated, historic first encounter.
Trump was quiet after touching down in Singapore on Sunday night but was back online first thing Monday morning, engaging Trudeau again in a war of words.
Experts believe the North is on the brink of being able to target the entire USA mainland with its nuclear-armed missiles, and while there's deep skepticism that Kim will quickly give up those hard-won nukes, there's also some hope that diplomacy can replace the animosity between the US and the North.
The two leaders are staying in separate hotels, not far from each other.
Trump is due to arrive later on Sunday.
Before leaving Canada he referred in a press conference to the meeting he will hold next Tuesday, at the Capella hotel on the tourist island of Sentosa.
The art of the unconventional deal?.
The meeting marks a sharp turnaround in the status of Mr Kim from worldwide pariah to global player.
Pyongyang has taken some steps to show sincerity, returning three USA detainees and blowing up the entrances to its nuclear test site. There was no need to.
"We have to get denuclearization". You'd start at least a dialogue. Rodman went on Instagram to announce that he will be there to "give whatever support is needed" for Trump and Jong Un. They are going to want a peace treaty, a security guarantee.
A "changed era" had come about, it said.
At 10am, North Korean vice-minister for foreign affairs, Choi Sun-hee, strode into the Ritz Carlton with her small team.
Mr Kim was driven to the city centre on Sunday in a stretch Mercedes-Benz limousine accompanied by a convoy of more than 20 vehicles.
Just meeting with Mr Trump will also give Mr Kim recognition as the leader of a "normal" country and as an equal of the U.S. leader.
Kim is scheduled to meet Trump at 9 a.m. local time on Tuesday to talk about ending his country's nuclear programme and transforming the isolated state which has been under harsh global sanctions for its defiant arms programme.
North Korea spent decades developing nuclear weapons, culminating in the test of a thermonuclear device in 2017. It also successfully tested missiles with enough range to reach the U.S. mainland. "We appreciate the working together with North Korea".
Japanese Prime Minister Shinzo Abe flew to Washington last week to meet with Trump before the G7 to ensure Japan's interests weren't overlooked in the summit.
Facing a pointed question about what he hoped to gain out of the summit, Trump responded with the following.