The following is a chronology of major developments in 2018 leading up to the third summit between South Korean President Moon Jae-in and North Korean Chairman Kim Jong-un in Pyongyang from Tuesday to Thursday.
Jan. 1 -- In his New Year's Day message, North Korean leader Kim Jong-un expresses a willingness to send a delegation to the PyeongChang Winter Olympics.
Jan. 4 -- President Moon Jae-in and US President Donald Trump agree to delay the allies' regular joint military exercises until after the Feb. 9-25 PyeongChang Winter Olympics.
Jan. 9 -- South and North Korea hold their first high-level talks in more than two years at the border village of Panmunjom.
They agree on the North's delegation's visit to the South during the Winter Olympics.
Feb. 9-11 -- North Korea sends a high-level delegation to the opening ceremony of the Winter Olympics that includes Kim Yong-nam, the nominal head of state, and Kim Yo-jong, a younger sister of North Korean leader Kim Jong-un.
Feb. 10 -- Kim Yo-jong delivers her brother Kim Jong-un's letter to President Moon Jae-in, which included an invitation to the South's leader to visit Pyongyang.
March 5-6 -- South Korean special envoys of President Moon Jae-in visit North Korea and meet with North Korean leader Kim Jong-un. They announce that South and North Korea have agreed to hold a summit of their leaders in late April.
March 28 -- North Korean and Chinese media say that North Korean leader Kim Jong-un visited China and met with President Xi Jinping. Kim reaffirmed his commitment to denuclearization during their first summit, Chinese media says.
March 29 -- South and North Korea hold high-level talks to discuss details about an inter-Korean summit. The two Koreas agree to hold a summit on April 27.
April 5 -- South and North Korea hold working-level talks to discuss protocol, security measures and media coverage for a summit slated for late April.
April 27 -- President Moon Jae-in and North Korean leader Kim Jong-un hold a summit at the truce village of Panmunjom. The two sides agreed to complete denuclearization and lasting peace on the Korean Peninsula.
May 24 -- North Korea shuts down its major nuclear test site in Punggye-ri in the country's northeast.
May 26 -- President Moon Jae-in and North Korean leader Kim Jong-un hold an unannounced second summit in Panmunjom.
June 12 -- US President Donald Trump and North Korean leader Kim Jong-un hold a summit in Singapore. They agree to build new relations, make joint efforts to establish a "lasting and stable"
peace regime on the peninsula and pursue the complete denuclearization.
July 31 -- The two Koreas share the understanding on a joint project to excavate Korean War remains in the Demilitarized Zone and the withdrawal of border guard posts on a trial basis during their general-grade military talks.
Aug. 9 -- North Korea proposes high-level inter-Korean talks over the implementation of the Panmunjom Declaration.
Aug. 13 -- The two Koreas agree to hold an inter-Korean summit in September during their high-level talks.
Sept. 5 -- South Korea's special envoy visits Pyongyang and meets North Korean leader Kim Jong-un.
Sept. 6 -- Chung Eui-yong, South Korea's chief presidential security advisor, announces that the leaders of the two Koreas will hold their third summit in Pyongyang from Sept. 18-20.
Sept. 14 -- The two Koreas open their joint liaison office in the North's border city of Kaesong.
Sept. 18-20 -- Moon and Kim are set to hold their third summit in Pyongyang. (Yonhap)