Since the end of the Korean War, the countries' relations have been marked by high tensions and periodic, but short-lived, thaws.

Here is a recap of their troubled history:

- A divided Korean peninsula -

In 1945 Japan's defeat in World War II ends its occupation of Korea. The peninsula is divided along the 38th parallel between the Soviet-backed regime of Kim Il-Sung in the North and a South under US protection.

In June 1950 North Korea, later assisted by China, invades the South. A coalition led by the United States retakes Seoul. In July 1953, an armistice -- not a full-fledged peace treaty -- is signed and Washington imposes sanctions on Pyongyang.

- Pueblo spy ship crisis -

In January 1968, the spy ship USS Pueblo is captured by North Korea. After 11 months, its 83 crew members are released. According to Pyongyang, the ship violated its territorial waters, a charge the United States denies.

In 1969, North Korea shoots down a US reconnaissance aircraft.

- Contacts -

In June 1994, former US president Jimmy Carter makes an unprecedented visit to North Korea.

In October, three months after the death of Kim Il-Sung and his succession by his son Kim Jong-Il, Pyongyang and Washington sign a bilateral agreement.

North Korea commits to freeze and dismantle its military nuclear program in exchange for the construction of civilian reactors.

In 1999, a year after its first test of a long-range ballistic missile, Kim Jong-Il declares a moratorium on missile tests and Washington eases sanctions.

In October 2000, US Secretary of State Madeleine Albright meets Kim Jong-Il in Pyongyang.

- Axis of Evil -

In January 2002, US president George W. Bush labels North Korea, Iran and Iraq an "axis of evil."

In October, Washington accuses Pyongyang of conducting a secret uranium enrichment program in violation of the 1994 agreement.

In August 2004, North Korea declares it is impossible to participate in a new nuclear program with the United States, attacking Bush as a "tyrant" worse than Hitler and a "political imbecile."

In 2006, Pyongyang conducts its first nuclear test.

- Off the US blacklist -

In October 2008, the United States withdraws North Korea from its blacklist of state sponsors of terrorism in return for controls on all of its nuclear installations.

Pyongyang had been on the blacklist since 1988 due to its suspected involvement in the bombing of a South Korean airliner in 1987 that killed 115 people.

- American detainees -

In January 2016, American student Otto Wambier is arrested and sentenced to 15 years of hard labor for allegedly stealing a propaganda poster.

He dies in June 2017, one week after being returned home to the US in a coma. Numerous Americans have been held for years before being repatriated. Three are currently detained there.

- Trump vs Kim -

On January 2, 2017, then US President-elect Donald Trump says North Korea will never be allowed to develop a nuclear weapon capable of reaching US territory.

In July, North Korea conducts two intercontinental ballistic missile tests. Kim declares: "The entire US territory is now within our ICBM range."

On August 8, Trump threatens "fire and fury" if Pyongyang continues to threaten the United States.

On August 29, Pyongyang test fires a ballistic missile over Japan. The US president says, "Talking is not the answer," although his defense secretary does not rule out diplomacy.

September 3, North Korea carries out its sixth nuclear test, announcing a "perfect test" of a hydrogen bomb that it claims can be mounted on a missile.

- War of words -

On September 21, Washington unveils tougher sanctions to curb North Korea's nuclear and ballistic missile program. The announcement comes on the heels of Trump's maiden speech to the UN General Assembly, in which he nicknames Kim "Rocket Man" and declares him to be on a "suicide mission."

A day later on September 22, Kim brands Trump "mentally deranged" and a "dotard", and warns he will pay dearly for his threats to destroy North Korea. As 2017 closes, Kim boasts his missile arsenal can hit any city on the US mainland.

On January 3, 2018, Trump raises eyebrows as he responds to Kim's New Year warning that he has a "nuclear button" on his desk. "I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!", he writes.

Pyongyang brands his outburst "the spasm of a lunatic" and the "bark of a rabid dog."

On February 25, North Korea slams what Trump describes as the "heaviest sanctions ever" as an "act of war."

Meanwhile, North Korean general Kim Yong Chol arrives in the South for the Winter Olympics closing ceremony -- also attended by Trump's daughter Ivanka -- part of North Korea's Olympic Games charm offensive.

- A historic invitation -

On March 8, 2018, in a remarkable announcement at the White House, South Korean national security advisor Chung Eui-yong says Kim has invited US Trump to meet by May, and will "refrain from any further nuclear or missile tests."

The White House says Trump has accepted the invitation, but does not set a date or locations for the talks, and adds that sanctions against North Korea will stay in place.