Trump said Wednesday he hopes to have a "very successful" meeting, but will walk away if it doesn't promise to be "fruitful."

Asked what her expectations are for the summit, Pelosi voiced cautious optimism that Kim is ready to abandon his nuclear weapons program.

"I wouldn't be too trustworthy of it, but certainly open to it," she said. "If at least the communication were increased, there could be some way to stop what could follow if left undeterred,

(if) North Korea were to continue what it's doing, which is, perhaps, other countries having access to the technology, the scientific know-how, the launch capacity and, dangerously, the intention."

The lawmaker recalled her past trip to Pyongyang as a member of the House Intelligence Committee, during which she said the North Koreans offered to sell their missile technology.

"So what my guidance from there to the current situation is the capability of the North Koreans to create either the technology for a weapon, the miniaturization of it, the capacity to launch it, and the intention to do so is something that we need to know as much about as possible," she said. "But in addition to that, they're proliferators. And this is what I keep saying to the administration. They are proliferators. So the danger is not just what they might do, the danger is who they might sell one element of that to, which might be enough to endanger the world even further."

Pelosi said North Korea was a "frightening" place.

"I saw poverty ... that just was mind-boggling in many respects. Even though their motto was self-reliance, they couldn't feed their own people," she recalled.

Mike Pompeo, Trump's new pick for secretary of state, made a secret trip to North Korea early this month to meet with Kim and prepare for the summit.

Pelosi said she hopes he is not confirmed by the Senate next week. (Yonhap)