SEOUL, Sept. 19 (UPI) -- North Korea entered a new era of openness in 2018, with an unprecedented RSVP to the 2018 Pyeongchang Winter Olympics and several face-to-face meetings with major world leaders since.
But even after North Korean leader Kim Jong Un clinked wine glasses with South Korean President Moon Jae-in and shook hands with U.S. President Donald Trump at the demilitarized zone, tension lingers.
North Korea has continued to launch several missile tests, and the United States hasn't budged on North Korea's request for the lifting of economic sanctions.
"A lot of people wanted to believe that, after the Panmunjom Summit, we were going to have a peace declaration soon. But that certainly hasn't resonated in Washington and nothing in [the U.S.'] calculation has changed," Jenny Town, a fellow at the Stimson Center and managing editor of North Korea analysis site 38North, told UPI. "Given the state of affairs, there is no guarantee that there will be a real negotiation between the U.S. and North Korea."
Here is a timeline of the reclusive regime's foray into more open international relations:
Jan. 9, 2018: Peace House, DMZ
North Korea decides to send athletes and a cheerleading team to the 2018 Pyeongchang Winter Olympics during its first high-level talks with South Korea in two years.
Feb. 9, 2018: Pyeongchang, South Korea
Moon shakes hands with Kim's sister, Kim Yo Jong, at the opening ceremony of the Winter Games. The two countries also established an inter-Korean women's ice hockey team.
March 25, 2018: Beijing
Kim Jong Un ventures out of North Korea for the first time since taking power in 2011 and meets Chinese President Xi Jinping in Beijing to discuss the two countries' "strategic partnership" and peace on the Korean Peninsula.
April 15, 2018: Pyongyang, North Korea
North Korean state media report that Song Tao, leader of the Chinese Communist Party's International Department, held a meeting with Kim to discuss mutual interests and "world order."
April 18, 2018: Pyongyang
U.S. President Donald Trump announces that Mike Pompeo, who was then CIA director, visited North Korea the week prior, ahead of a U.S.-North Korea summit.
April 27, 2018: DMZ
Moon and Kim meet for the first time face to face at the Joint Security Area in the DMZ. The two leaders signed the historic Panmunjom Declaration, which promised to develop inter-Korean relations, reduce military tensions, establish peace on the Korean Peninsula and work toward "complete denuclearization."
May 7, 2018: Dalian, China
Kim meets with Xi for the second time in 40 days. The two leaders met for two days -- a "surprise move" ahead of Kim's planned summit with Trump.
May 9, 2018, Pyongyang
Now Secretary of State, Pompeo meets with Kim to finalize plans for a summit with Trump. Three detained Americans return home with Pompeo.
May 26, 2018: DMZ
Moon and Kim meet again at the Joint Security Area to discuss inter-Korean cooperation and denuclearization.
June 12, 2018: Singapore
Trump and Kim meet face to face for the first time, signing a joint statement reaffirming that the two countries pledge "to build a lasting and stable peace regime on the Korean Peninsula."
June 18, 2018: Beijing
Kim makes his third visit to China to meet with Xi.
July 24, 2018: Tongch'ang-ri, North Korea
Reports surface that North Korea has begun dismantling key weapons facilities, including a missile transfer structure and a rocket engine test stand.
July 27, 2018
North Korea repatriates the remains of 55 individuals killed during the Korean War, some of whom are believed to be U.S. soldiers.
August 20, 2018: Mount Kumgang, North Korea
Dozens of families divided by the Korean War begin meeting for brief reunions at the tourist resort. The families, which include 89 South Koreans and 83 North Koreans, are selected by a lottery system and are given only a few hours to meet after more than 65 years apart.
Sept. 18, 2018: Pyongyang
Moon meets Kim for a two-day summit to discuss inter-Korean cooperation and denuclearization. The leaders sign an agreement pledging to work on a number of cooperative measures, including reunions between Korean families separated by the border and to participate together at the 2020 Summer Olympic Games.
Oct. 7, 2018: Pyongyang
Pompeo makes his fourth visit to Pyongyang to meet and dine with Kim. The two discussed U.S.-North Korea relations for a total of 5 ½ hours.
Jan. 7, 2019: Beijing
Kim meets with Xi for a fourth time over a span of several days, partly to celebrate the two nations' 70-year anniversary of diplomatic ties.
Feb. 27, 2019: Hanoi, Vietnam
Trump and Kim meet for their second face-to-face summit. The next day, Trump abruptly ends the meeting before lunch, reportedly over a disagreement over sanctions relief negotiations.
April 25, 2019: Vladivostok, Russia
Kim and Russian President Vladimir Putin meet for the first time for a "no-deal" summit.
May 9, 2019: North Korea
North Korea fires short-range missiles off the eastern coast. The missiles surpassed an altitude of 30 miles.
June 12, 2019: Panmunjom
Kim Yo Jong, delivers a letter to South Korean national security adviser Chung Eui-yong expressing condolences on the death of former South Korean first lady Lee Hee-ho, who died June 10.
June 20, 2019: Pyongyang
Xi meets with Kim for a two-day summit in Pyongyang. North Korea's state newspaper said the meeting was meant to "push forward the political settlement of the Korean Peninsula issue and maintain peace and stability in the region."
June 30, 2019: DMZ
Trump and Kim meet briefly for a short talk and photo opportunity. Trump stepped past the dividing line and into North Korea, becoming the first sitting U.S. president to enter the country.
July 25, 2019: North Korea
North Korea launches two short-range ballistic missiles from its east coast as a "solemn warning" to South Korea over upcoming joint military exercises with the United States.
July 30, 2019: North Korea
North Korea launches two additional projectiles into the sea from its Hodo peninsula in South Hamgyong province.
Aug. 7, 2019: North Korea
North Korean state media announces that it conducted a set of missile launch tests a day earlier as a "warning" to South Korea and the United States, which had just begun routine joint-military exercises.
Aug. 9, 2019: North Korea
North Korea fires two unidentified projectiles into the East Sea.
Washington, D.C.
Trump announces that he received a "beautiful letter" from Kim. He later said the letter apologized for missile testing and complained about the military drills.
Aug. 16, 2019: North Korea
North Korea launches two short-range projectiles and puts out a statement criticizing Moon's Liberation Day speech that promised to set the grounds for denuclearization by 2022 and reunify the Korean Peninsula by 2045.
Aug. 17, 2019: North Korea
North Korean state media announce a short-range ballistic missile test supervised by Kim -- the sixth test in a month.
Aug. 24, 2019: North Korea
North Korea launches two missiles, traveling about 240 miles before landing in the East Sea. The missile launch followed joint military exercises between South Korea and the United States, which North Korea publicly called a "rehearsal for war."
Sept. 10, 2019: North Korea
North Korea's Vice Foreign Minister Choe Son-hui announces that North Korea wants to resume nuclear talks with the United States in September, but North Korea fires an "unidentified projectile" into the East Sea as a weapons test hours later.
Elizabeth Shim, Thomas Maresca, Wooyoung Lee and Jennie Oh contributed to this report.
