"What he did was criminal, what he did was a awful thing to the people, what he did was so bad, in terms of our Constitution, in terms of the well-being of our country", Trump said. He said he would be including Beijing in follow-up discussions.
"Hey, he's the head of a country, and I mean, he's the strong head - don't let anyone think anything different", Trump said. In return, Mr. Trump agreed to stop the ongoing joint military exercises with political ally South Korea and establish diplomatic relations with North Korea.
North Korea runs a particularly brutal regime with unparalleled restrictions on citizenry and its vast gulag system.
"Making unnecessary and unreciprocated concessions is not in our interests - and it is a bad negotiating tactic", Republican Senator John McCain said. Trump talks directly to the camera and praises his talks with Kim as "open, honest, direct and very, very productive". "I want my people to do the same".
Following his remarks, the President later emphasised his remarks were "sarcastic" when asked by reporters at the White House.
Trump has sounded a triumphant tone since the summit in Singapore, where he and Kim signed a joint statement in which the North Korean leader committed "to work toward complete denuclearisation of the Korean Peninsula".
"Once we know that it can't happen", he said of further nuclear and missile tests. Trump - who has long pitched himself as a master dealmaker - feels the agreement represents a radical step toward solving an intractable foreign policy problem and has been publicly and privately grumbling that not everyone agrees.
And Friday's Fox and Friends interview was not the first time that Trump voiced admiration for Kim.
Part of Trump's agreement with Kim involves the repatriation of the bodies of several thousand United States servicemen, lying in North Korea since the Korean War was put on hold by ceasefire in 1953, a point that the president talked up several times on Friday.
"Because I don't want to see a nuclear weapon destroy your family", he said.