"Mike Pompeo did go there, he wasn't supposed to meet with Kim Jong Un, but he did," Trump told "Fox and Friends." "You know they arranged actually while he was there to say hello."
Trump then added that the two spoke for more than an hour and that they have "incredible pictures of the two talking and meeting."
The meeting between the Korean leaders, set for Friday local time, signals a reduction in tensions on the Korean peninsula. It will be the first face-to-face summit since 2007.
While the details of Trump's unprecedented meeting with Kim remain to be seen, the president said he is considering four dates and five locations.
"I can only say this, when I came into office people thought we were going into nuclear war and now they're saying wow this is going to be taken care of," Trump said.
Trump added that tensions on the Korean peninsula were getting "very, very nasty" and that discussions with the communist North should have happened before his presidency. Four months ago, Kim and Trump traded bellicose rhetoric about the relative size of their nuclear buttons.
"This is a much different ballgame than if they did it five or 10 or 20 years ago. This is a much more dangerous ballgame now but I will tell you that it is going very well," Trump said.