Transcript for President Trump's mission to convince North Korea to give up its nuclear weapons

A rogue nation all. Armed with nuclear weapons led by an unpredictable. Dictator executive very very badly and a war of words raising fears the world was on the brink of a real war. You want to do needy he had pretty excellent running into him. They won't be met. When fire and fury like the world has never seen a twin seventeen North Korea launched over a dozen missiles. Among those that Intercontinental ballistic missile last July. The highest and farthest North Korea missile launch ever US intelligence analysts said it had the capability of reaching the US mainland. Credit where you look back North Korea. It's September the regime detonator the hydrogen Baum its sixth and most powerful nuclear test to date. Continuing to provoke the president rocket man. Is on a suicide mission for himself. And for his regime he announced punishing new economic sanctions and the Pentagon prepared military options but they did. It on expected ball. North and South Korea teamed up for the Winter Olympics in pee on Chang in April a series of diplomatic breakthroughs. Secretary of state Mike Pompeo made a secret trip to Pyongyang. Paving the way for president trump to be the first American president. To meet with the North Korean dictator he administration's goal convinced North Korea to give up their nuclear weapons. Flurry of gestures from North Korea followed the regime vowed to suspend nuclear and long range missile tests. And shut down nuclear tests are and North Korea released three America. They are really three incredible people in early may the date for this unprecedented. Summit was set. President trump came into this confident in his negotiating skills I think number were prepared. Don't forget to prepare very much about attitude for Nightline I'm Jonathan Karl in Singapore.

This transcript has been automatically generated and may not be 100% accurate.