Donald Trump said he believes North Korean leader Kim Jong-un wants to bring “his country into the real world” after overseeing the release of three American detainees Thursday.

Trump and his wife Melania were at Joint Base Andrews in Maryland to greet Kim Dong Chul, Kim Hak-song and Kim Sang Duk, who were released as part of a “pre-bargain” agreement with the North Korean leader. U.S. news networks covered the meeting at around 3 AM local time.

After meeting the three on board the plane, which also included Secretary of State Mike Pompeo, and with VP Mike Pence and his wife Karen also in attendance, Trump addressed the media.

“I really think he wants to do something and bring his country into the real world,” Trump said. “I think this will be a very big success. It’s never been taken this far, there’s never been a relationship like this. Some great things can happen, and that’s what we hope.”

He added: “This is a special night for these three really great people. Frankly, we didn’t think this was going to happen, and it did. It was a very important thing to all of us.”

Dong Chul, who said he had been forced to do hard labor but also received medical treatment in North Korea, said, “It’s like a dream and we are very, very happy.”