In their second meeting in eight months, President Trump and North Korean dictator Kim Jong Un exchanged warm smiles and handshakes in front of cameras at a luxury hotel in Hanoi early Wednesday. Mr. Trump said negotiations over North Korea's denuclearization are proceeding apace, although little noticeable progress has been made.

The concern this time is Mr. Trump might take a short-term win with no real long-term benefits, according to "Face the Nation" moderator Margaret Brennan. She told "Evening News" anchor Jeff Glor a cessation of testing by North Korea would make Mr. Trump happy.

The type of deal Mr. Trump promised requires a detailed, sequenced process by which North Korea agrees to allow inspectors and dismantle its weapons programs, which Brennan points out will take far more time. She also said not everyone in the Trump administration is one the same page concerning North Korea.

U.S. President Donald Trump and North Korean leader Kim Jong Un shake hands before their one-on-one chat during the second U.S.-North Korea summit at the Metropole Hotel in Hanoi, Vietnam, on Feb. 27, 2019. Reuters

Mr. Trump is eager for a deal, but that contracts sharply with National Security Adviser John Bolton who wants to proceed with caution.

Meanwhile, having two unpredictable leaders in the same room makes diplomats extremely nervous, Brennan said. At the last summit in Singapore, Mr. Trump went out to the press and announced something that negotiators in the room had not agreed to: The suspension of military exercises — which caught even the U.S. government by surprise.

On Wednesday, speaking through an interpreter, Kim said some "misunderstandings" and "hostility" remain, but he thanked Mr. Trump for what he called his "courageous" decision to meet, as CBS News chief White House correspondent Major Garrett reported from Hanoi.

After a brief one-on-one meeting, the two leaders shared dinner. Mr. Trump divulged no details of their private meeting, but offered a tease.

"Boy if you could've heard that dialogue. If you could've paid for that dialogue. It was good," Mr. Trump said.

Garrett said Mr. Trump expressed optimism ahead of Thursday's negotiations.

"I think they will be very successful. Great relationship ... we look forward to it," Mr. Trump said. "We both do."