The following is a chronology of major developments in the relations between the United States and North Korea in 2018 leading up to the first-ever summit between Donald Trump and Kim Jong-un on Singapore's resort island of Sentosa on Tuesday.

2018

March 8 -- Chung Eui-yong, South Korean President Moon Jae-in's top security advisor, and Suh Hoon, chief of the National Intelligence Service, meet with US President Donald Trump in Washington and convey North Korean leader Kim Jong-un's intention to invite him to Pyongyang. Trump accepts the invitation and announces that he will meet Kim in May.

March 31-April 1 -- Mike Pompeo, director of the Central Intelligence Agency and nominee for US secretary of state, meets with North Korean leader Kim Jong-un in Pyongyang to prepare for the summit.

April 9 -- US President Donald Trump expresses his hope of meeting North Korean leader Kim Jong-un either in May or June during a Cabinet meeting. 

April 27 -- South Korean President Moon Jae-in and North Korean leader Kim Jong-un hold their first inter-Korean summit at the truce village of Panmunjom.

May 9 -- Secretary of State Mike Pompeo makes a second trip to North Korea and meets leader Kim Jong-un.

May 10 -- Secretary of State Mike Pompeo returns to the US with three Americans detained in North Korea. On the same day, US President Donald Trump tweets that his summit with North Korean leader Kim Jong-un will take place in Singapore on June 12.

May 12 -- North Korea announces its plan to dismantle its only known nuclear test site in Punggye-ri.

May 16 -- North Korea unilaterally cancels high-level inter-Korean talks, taking issue with ongoing joint military drills between South Korea and the US Kim Kye-gwan, North Korea's vice foreign minister, issues a statement threatening to pull out of the planned summit with the US, citing hostile remarks by US officials.

May 24 -- Choe Son-hui, the North's vice foreign minister, issues a statement threatening again to withdraw from the planned summit with the US The North dismantles its Punggye-ri nuclear test site in front of a group of invited international media people. Later the same day, US President Donald Trump says in an open letter to North Korean leader Kim that he is cancelling the summit with him, citing "tremendous anger and open hostility" from the North. 

May 25 -- North Korea's Vice Foreign Minister Kim Kye-gwan issues a statement expressing a desire to have talks with the US.

May 26 -- South Korean President Moon Jae-in and North Korean leader Kim Jong-un hold their second summit at the truce village of Panmunjom in an apparent bid to salvage the US-North Korea summit.

May 27 -- The US and North Korea hold working-level consultations at the truce village of Panmunjom for a summit between their leaders.

May 31 -- US Secretary of State Mike Pompeo and Kim Yong-chol, vice chairman of the central committee of North Korea's ruling Workers' Party, meet in New York.

June 1 -- Kim Yong-chol, vice chairman of the central committee of North Korea's ruling Workers' Party, meets US President Donald Trump in Washington and conveys his leader's letter to him. Trump confirms that his summit with North Korean leader Kim Jong-un will take place as planned in Singapore on June 12.(Yonhap)