President Donald Trump said Sunday he expects his second meeting with North Korean leader Kim Jong Un to take place early in 2019 and said he expects Kim to visit the U.S "at some point" in the future.

"I have a very good relationship with Kim Jong Un," Trump told reporters aboard Air Force One on his return flight from the Group of 20 meeting in Argentina. He touted the progress he has made negotiating with the communist ruler, saying his administration had only been dealing with North Korea for a short time, after "people have been working on that one for 80 years, right?"

"And 20 years with the nuclear – you know, if you just take the nuclear. But he is agreeing to work with me 100 percent on North Korea, and that’s a big thing, too," Trump said.

The president said he expects a second summit with Kim to be held in January or February.

"We’re getting along very well," he added. "We have a good relationship."

During a Nov. 7 news conference, Trump said he expected the meeting to take place "sometime next year" and stressed that he was "in no rush."

In sharp contrast to his previous bombastic attacks on "Little Rocket Man," the president has been very positive in his assessment of Kim since their meeting in Singapore on June 12, where the two leaders committed to "denuclearization" of the Korean Peninsula without offering any specifics on how or when that would occur.

His more friendly approach to the North Korean leader has continued even as reports indicate Kim has continued his program to develop nuclear weapons. But Trump has emphasized the end of Kim's missile tests and the return of the remains of American soldiers killed in the Korean War.

When asked if he expected Kim to visit the U.S., Trump said, "At some point, yeah."

Trump did not clarify if his second summit with Kim could potentially be held in the U.S., but said: "We have actually talked about three sites. We haven’t determined the sites."

Trump said Kim plans to make the powerful opioid fentanyl illegal and "the highest level of crime in his country."

"That could be a game changer," in the U.S. battle against opioid addiction, Trump said.

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