Speaking at a business conference in Tel Aviv, Rudy Giuliani – the former mayor of New York – said the billionaire tycoon only had the meeting rescheduled after Pyongyang was forced to soften its stance.
He said the president had been left with no choice but to cancel after Mr Kim insulted the vice president Mike Pence and threatened nuclear war.
Mr Giuliani said: “Kim Jong Un got back on his hands and knees and begged for it, which is exactly the position you want to put him in.”
The historic summit between the two countries is now set to take place on 12 June in Singapore.
The announcement that the meeting was back on followed a meeting between Mr Trump and senior North Korean official Kim Yong Chol, who arrived at the White House to hand-deliver a letter from the country’s leader.
Speaking to reporters afterwards, Mr Trump said the meeting had been a “getting to know you kind of situation” and that “the relationships are building and that’s very positive”.
Their meeting came after the North Korean envoy met Secretary of State Mike Pompeo, who described the preliminary discussions as “good” and “moving in the right direction”.
“Our two countries face a pivotal moment in our relationship, and it would be nothing short of tragic to let this opportunity go to waste,” he said, adding that he believed North Korea was “contemplating a strategic shift”.
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Mr Giuliani, who has been advising Mr Trump amid the probe into Russian interference in the 2016 election, also took aim at special counsel Robert Mueller’s team, accusing its members of trying to frame President Trump.
At Wednesday’s event, the 74-year-old said the team was made up of “13 highly partisan Democrats… (who) are trying very very hard to frame him (Mr Trump) to get him in trouble when he hasn’t done anything wrong”.