North Korea summit: What success is for Trump, Kim Jong Un

Success for President Trump can be measured in three ways during his historic meeting with North Korean leader Kim Jong Un, Robert Charles, former assistant secretary of state to President George W. Bush, told FOX Business on Monday.

Trump will be the third foreign leader that Kim has met with since taking power in 2011.

"At the end of the day just sitting down to engage in conversations" during this time is an “enormous success,” Charles told Neil Cavuto on “Cavuto: Coast to Coast,” but he also weighed the importance of walking away with an agreement that defines denuclearization.

“Which means that they agree that denuclearization is either the disarmament or the elimination of those weapons and the capacity to create them,” he said.

Secondly, it’s important to distinguish what the future holds for bilateral meetings.

“A next step … which is the idea that you will … have another meeting of principals,” he said. “It won’t necessarily be right away with presidents but you’ll go to the next level.”

And finally – and most importantly – he said, is the meeting of the minds.

“When this thing is said and done, both walk away with the perception that they can agree that there is mutual benefit in getting rid of the nuclear weapon, perhaps economic and security benefit, and that China buys into it,” he added.