March 8: US President Donald Trump accepts North Korean leader Kim Jong Un's invitation to meet.
March 25: Mr Kim travels to Beijing to meet Chinese President Xi Jinping. They meet again in Dalian on May 7.
March 31: CIA chief Mike Pompeo meets Mr Kim in Pyongyang.
April 21: Mr Kim announces that his regime will dismantle its nuclear test site. The site is demolished on May 24.
April 27: Mr Kim and South Korean President Moon Jae In hold a historic summit.
April 29: US National Security Adviser John Bolton floats the "Libya model" for North Korea. Libyan leader Muammar Gaddafi gave up atomic weapons in 2003 for sanctions to be lifted, but was killed by US-backed rebels in 2011.
May 9: Mr Pompeo, now Secretary of State, visits Pyongyang and returns with three detained Americans.
May 10: Mr Trump announces he will meet Mr Kim on June 12 in Singapore.
May 16: Pyongyang berates the US for pushing the "Libya model".
May 21: US Vice-President Mike Pence warns North Korea could end up like Libya.
May 24: North Korea calls Mr Pence "stupid" and threatens to cancel the summit. Mr Trump cancels the summit, citing the North's hostility.
May 25: After receiving a conciliatory response from Pyongyang, Mr Trump says the summit might proceed.
May 26: Mr Kim and Mr Moon agree to push for Trump-Kim summit.
May 27: US and North Korean envoys meet in the North. Separate teams meet in New York and Singapore .
June 1: Mr Kim's right-hand man delivers a letter to Mr Trump at the White House. Mr Trump declares that the June 12 summit is back on.
Lee Seok Hwai