CHICAGO (CBS) — President Donald Trump left Singapore on Tuesday, after wrapping up an unprecedented meeting with North Korean dictator Kim Jong Un.

The president said he expects it will be just the first of many one-on-one meetings for the two leaders.

The pair shook hands before spending time in private meetings, having lunch, and then signing an agreement including North Korea’s commitment work toward denuclearization. In exchange, the U.S. will end joint military exercises with South Korea.

“My meeting with Chairman Kim was honest, direct, and productive. We got to know each other well in a very confined period of time; under very strong, strong circumstances. We’re prepared to start a new history, and we’re ready to write a new chapter between our nations.”

Trump said North Korea already has started the process to get rid of its nuclear weapons, and he believes this is the beginning of world peace.

A signed agreement between Trump and Kim outlines four major points, including lasting peace and prosperity between the two nations, North Korea’s commitment to work towards complete denuclearization, and the commitment to recover the remains of prisoners of war and military members missing in action.

Both nations negotiated for months. Trump said the agreement is comprehensive, and there will be ways for the U.S. to verify the process to check on North Korea.

“It’s going to be there. It’s going to happen. People thought this could never take place. It is now taking place. It’s a very great day. It’s a very great moment in the history of the world,” Trump said. “If I can save millions of lives by coming here, sitting down, and establishing a relationship with someone who’s a very powerful man, who’s had firm control of a country, and that country has very powerful nuclear weapons, it’s my honor to do it.”

The president said he’s confident Kim will follow through on his words. As for the timeline when North Korea’s nuclear weapons will be destroyed, Trump said it’s going to take time due to the scientific and mechanical aspects.

Sanctions against North Korea will remain in place until denuclearization occurs.

Trump was the first American president to meet with Kim Jong Un. He said he will absolutely invite Kim to the White House.

“He actually brought it up to me, and he said we have never gone this far. I don’t think they’ve ever had the confidence, frankly, in a president,” he said.