"I think [Kim] didn't realize who Donald Trump was at that time, I guess, until he started to read the book and started to get to understand him".
Russian President Vladimir Putin has pledged that his country will make sure that President Donald Trump's upcoming meeting with North Korean leader Kim Jong Un is a success.
Experts have voiced concern that despite Trump's claim to be the world's greatest dealmaker, he knows little about North Korea, arms control or worldwide diplomacy.
The US is pushing for a "complete, verifiable and irreversible" end of North Korea's nuclear weapons and missile programmes, but observers believe there is a large gap between what Washington and Pyongyang define as "denuclearisation".
He said there was no choice but to cancel the June 12 summit after Mr Kim insulted the US Vice President and threatened nuclear war.More news: Former quarterback Oliver Luck to become XFL commissioner
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Two people familiar with the relationship between Pompeo and Bolton said Pompeo is skeptical of Bolton and does not trust his views on dealing with North Korea.
The US delegation had been based at the Capella Hotel last week during talks with Mr Kim Chang Son, the de facto chief of staff for North Korea.
"I can tell you the schedule - tentatively - for that first meeting, will be on June 12 at 9 am Singapore time", she added.
Meanwhile, Kim Chang Son, who is often referred to as Kim's "butler" and led the pre-summit talks with the US delegation in Singapore, flew from there to Beijing on Wednesday.
Trump also said that there would be no new sanctions while the talks are taking place, although the White House was at pains to say existing economic sanctions will not be removed either.