After decades of nuclear tension on the Korean peninsula, South Korea says North Korean leader Kim Jong Un is proposing talks with the South and the United States.
Previous attempts to persuade North Korea to back off its nuclear weapons programme failed amid the North's reversals and enmity between Pyongyang and Washington.
The following describes previous rounds of talks:
2003-2009: SIX-PARTY TALKS
In January 2003, North Korea's Kim Jong Il, father of Mr Kim Jong Un, announces that Pyongyang will withdraw from the Non-Proliferation Treaty it had agreed to in 1985. Three months later, North Korea announces it has a nuclear weapon.
In hopes of finding a peaceful resolution to the North's nuclear ambitions, six-party talks begin in Beijing between North Korea, South Korea, China, the US, Russia and Japan.
In 2004-2005, North Korea continues missile testing. As would become a pattern, Pyongyang offers to curtail its work in exchange for aid, while also citing concerns about hostile action from the US.
With the six-nation talks in abeyance in 2006, the North steps up missile testing and accuses the US of being a nuclear menace.
The sixth round of the talks open in February 2007, and North Korea promises to shut its nuclear reactor in exchange for fuel oil. It later demands that the US release US$25 million in frozen funds, which it gets in June, clearing the way for another round of talks a month later.
A North Korean pledge to disclose all its nuclear activities by the end of the year goes unfulfilled.
In May 2008, North Korea demands that the US remove it from its list of state sponsors of terrorism and Washington complies in October, prompting the North to resume tearing down its Yongbyon nuclear plant.
In 2009, the United Nations Security Council responds to a North Korean missile test by threatening to increase sanctions, and Pyongyang, which had baulked at verification efforts, says it will no longer participate in the six-party talks.
1994-2002: NORTH KOREA-U.S. TALKS UNDER CLINTON, BUSH
In 1994, North Korea and the US, under President Bill Clinton, sign an "agreed framework" with the goal of freezing and eventually discontinuing Pyongyang's nuclear programme. In exchange, North Korea has the possibility of normalised relations, fuel oil and help building light-water nuclear reactors.
North Korea's production and sale of missiles become an issue. Talks begin with the US pushing the North to curtail the missile business. In 1998, sanctions are imposed on the North for sending missile technology and parts to Pakistan.
Despite several rounds of talks, no firm agreement is reached on missiles.
When Mr George W. Bush becomes president in 2001, Pyongyang detects a more hostile attitude, and US sanctions are imposed on a North Korean company for missile-related transfers to Iran, according to the Arms Control Association.
Relations are frayed further in 2002 when Mr Bush labels North Korea, along with Iran and Iraq, as part of an "axis of evil" spon-soring terrorism and seeking nuclear weapons.
The agreed framework breaks down in December 2002 as the US determines North Korea has been secretly pursuing nuclear weapons. The North accuses the US of delaying promised deliveries of oil, and orders international inspectors out of the country while reopening its shuttered nuclear facilities.