"I call them war games".
Trump on Wednesday hailed his meeting with Kim as having removed the North Korean nuclear threat, but Harris told the panel "I think we must continue to worry about the nuclear threat". "He speaks and his people sit up in attention". He did not elaborate.
Later, Trump unexpectedly made his way through a crowd of White House reporters and was asked about everything from Russian Federation to North Korea and China.
"I'm going to be calling North Korea", he said.
Trump was responding to criticism that he gave Kim the propaganda win of a summit without getting more concessions on denuclearization, and didn't lock in a plan to get there.
"I want my people to do the same", Trump said, before joking about the fate of several North Korean generals.
With tongue in cheek, he added, "I want my people to do the same".
South Korea, US to announce whether to suspend joint drills
Trump gestured toward White House when he made the comment, suggesting he was referring to his staff. And he said North Korea is on the road to denuclearization.
The one-day summit, aimed at reducing the threat from nuclear-armed North Korea, went ahead as planned on Tuesday.
According to Trump, the two leaders privately discussed human rights and Kim reacted "very well".
Mr Trump's nominee as next ambassador to South Korea, Harry Harris - previously a supporter of the drills - has said that "major exercises" should be paused to allow time to test Pyongyang's commitment about dialogue. "Maybe I'll have to take an unannounced trip down to see them?" he said.
Trump later told a reporter he was being sarcastic.
Trump answered a question Wednesday on Fox about abuses carried out under Kim by saying that "a lot of other people done some really bad things".
Trump was asked during a Fox News Channel interview outside the West Wing if he would invite Kim to the White House. Yeah, I think it is something that could happen. "And that is the president of the United States is just outside the press room and it looks like he is en route to our location".
Trump says: "Our world has seen more than enough conflict".
Russian giant Gazprom had the idea to deliver 10 bcm of natural gas to the resource-poor and import-dependent South Korea by pipeline, but its route must pass through the territory of North Korea.
He said he "spoke with China" about the summit and "they're very happy", although he added that "they may not be as happy today" after the USA approved a plan to impose tariffs on $50 billion of imports from China.