President Donald Trump and North Korean leader Kim Jong Un are set to meet at the negotiating table in Singapore on Tuesday in a dramatic reversal from last year’s insults and brinkmanship.

The road to the historic meeting — the first between a sitting U.S. President and a North Korean leader — has been fraught with ups and downs.

1994: President Bill Clinton’s administration and North Korea sign a deal known as the Agreed Framework. Under the terms, Pyongyang commits to freezing its illicit plutonium weapons program in exchange for U.S. construction of light-water nuclear reactors, heavy fuel, normalized relations and formal assurances against the threat or use of nuclear weapons.

2002: North Korea once again begins operating its nuclear facilities.

2003-2007: Multilateral discussions among China, Japan, North Korea, Russia, South Korea and the U.S. — known as the Six-Party Talks — seem to take a step forward when North Korea pledged to abandon its existing nuclear programs. Pyongyang also pledges to return to the Nonproliferation Treaty, which the country said it had decided to leave two years prior after originally entering it back in the 1980s. The deal appears to be a diplomatic win for the U.S. administration of George W. Bush.

2006: Pyongyang launches its first nuclear test, but the Six-Party Talks continued.

2007: North Korea begins disabling its Yongbyon nuclear plant. But that good will didn’t last.

2008: The regime restarts its nuclear program and barred nuclear inspectors.

2009: North Korea officially quits nuclear talks.

December 17, 2011: Kim Jong Un takes office as the third Supreme Leader of North Korea following the death of his father.

March 2013: North Korea adopts an official policy of developing both the country’s economy and its nuclear capabilities.

January 2016: North Korea, which has continued testing its ballistic missiles technology, claims its first successful hydrogen bomb test. Some experts disputed Pyongyang’s characterization of the weapon.

August 2016: North Korea claims to launch a Pukkuksong-1 missile capable of striking the United States. The missile is a submarine-launched ballistic missile.

October 2016: There are two failed missile launches — one was a ballistic missile, the other was an intermediate-range missile.

January 2017: Trump begins his term as president of the United States. His predecessor, Barack Obama, had reportedly warned him that North Korea should be a top security priority for the incoming administration.

February 2017: North Korea test-fires a new medium-range ballistic missile. The KN-15 (Pukkuksong-2) is launched from the North Pyongan province and travels 310 miles before landing in the Sea of Japan.

March 2017: North Korea fires four missiles, with some falling into the Sea of Japan. Japanese officials described the launches as a grave threat and said they lodged “strong protests” with nuclear-armed North Korea.

April-June 2017: North Korea conducts several more missile tests, ratcheting up international fears. During this period, liberal leader Moon Jae-In wins the presidency in South Korea, vowing to make inroads with Pyongyang. The new president acknowledges, however, that there is a “high possibility” of conflict with his northern neighbor.

July 2017: North Korea tests its first intercontinental ballistic missile on July 4. That is swiftly followed by a second test later in the month.

August 2017: North Korea tests four ballistic missiles over the course of three days — with one flying over Northern Japan. South Korea’s Moon promises to prevent war with the North “by all means.” In the U.S., meanwhile, Trump says, “North Korea best not make any more threats to the United States,” warning that the country would “met with fire and fury like the world has never seen.”

September 2017: North Korea claims it has a “perfect success” with a test of a hydrogen bomb. H-bombs are a form of atomic weapon that is more difficult to develop and carries massive destructive power. Later in the month, the country launches another missile that flies over Northern Japan. On the diplomatic front, Trump signs an executive order that aims to expand his authority to target people and institutions doing business with North Korea. Kim follows that with a statement saying he will “surely and definitely tame the mentally deranged U.S. dotard with fire.”

November 2017: North Korea launches an intercontinental ballistic missile that flew into the Sea of Japan.

January 2018: North Korea accepts South Korea’s offer for talks.

February 2018: Korean unity is on display at the Olympics as Seoul hosts hundreds from North Korea for the Winter games. The two Koreas combine their women’s ice hockey team at the Pyeongchang Games in a symbol of peaceful engagement.

March 2018: North Korea asks for nuclear talks with the United States, and Trump says he will take the rogue nation up on the offer. Kim visits Beijing via train, meeting with Chinese President Xi Jinping in what is his first known trip abroad since assuming power.

April 2018: Pyongyang says it will suspend nuclear tests. Kim and South Korean President Moon Jae-in meet, hug and hold hands at the Korean border in a historic meeting of the two Koreas.

May 2018: Trump says his summit with Kim will take place on June 12 in Singapore. Just two weeks later, Trump cancels the meeting with Kim, accusing Pyongyang of “tremendous anger and open hostility.” A few days later, the White House says the meeting is back on.

June 2018: Trump and Kim land separately in Singapore on June 10, and then separately meet with the island nation’s prime minister. The North Korean and American leaders are set to meet each other at 9 a.m. local time on June 12.

—CNBC’s Nyshka Chandran, Christine Wang and Amanda Macias and Reuters contributed to this story.