North Korea agreed on Wednesday to stop nuclear tests, uranium enrichment and long-range missile launches, and to allow nuclear inspectors to visit its Yongbyon nuclear complex, opening the way to a possible resumption of six-party disarmament negotiations with Pyongyang.
The announcement followed talks between U.S. and North Korean diplomats in Beijing last week, the first official contacts since the death of North Korean leader Kim Jong-il.
The United States said in return for the communist state's nuclear moratorium, it was ready to finalize details of a proposed 240,000 metric tons food aid package to help the North cope with chronic food shortages.
U.S. officials remained skeptical of Pyongyang's commitment after earlier deals were unfulfilled. Here is a look at past disarmament deals and how they have unraveled.
NORTH KOREA JOINS NUCLEAR TREATY, BUT DEFIES DUTIES
North Korea joins the Nuclear Nonproliferation Treaty in 1985 but does not sign a safeguard deal with the International Atomic Energy Agency (IAEA) for years, demanding U.S. forces withdraw from South Korea.
The North completes a safeguard agreement in 1992 but fails to fulfill disclosure requirements and refuses full IAEA inspections. Amid growing concern the North is working to build nuclear weapons, there are reports that the United States plans to bomb key sites in the North, raising the possibility of war.
AGREED FRAMEWORK DISARMAMENT DEAL OF 1994
Former U.S. President Jimmy Carter visits the North and meets the North's supreme leader, Kim Il-sung, who agrees to hold disarmament talks with Washington. Kim dies, throwing into question his pledge to negotiate a resolution to the crisis, but subsequent talks lead to the "Agreed Framework" deal.
Under the deal, the North will freeze its nuclear facilities and dismantle them in return for two lightwater reactors and fuel oil while the plants are being built. Tension is defused as Washington and Pyongyang exchange high-level visits, but work on the construction of the lightwater reactors under the 1994 deal falls behind schedule.
BREAKDOWN OF 1994 ACCORD
U.S.-North Korea ties chill quickly after George W. Bush takes office in Washington in 2001 and calls the North part of an "axis of evil."
North Korea refuses safeguard steps by the U.N. nuclear watchdog, the International Atomic Energy Agency.
U.S. envoy James Kelly visits Pyongyang in 2002 and confronts North Korean officials with a charge that Pyongyang is running a uranium enrichment program in violation of the 1994 deal.
The North kicks out nuclear inspectors and says it is restarting its nuclear plant because Washington broke the 1994 accord. In late 2002, the North declares the pact has collapsed.
SIX-PARTY TALKS -- THE BEGINNING
Talks begin in August 2003 in Beijing among the two Koreas, the United States, Japan, Russia and China amid concern that the North is increasing its stockpile of weapons-grade plutonium.
LANDMARK DEAL
At the conclusion of four rounds of talks, the six parties agree on a framework deal in September 2005 under which the North gives up its nuclear program in return for massive economic and energy aid and an end to its diplomatic isolation.
North Korea boycotts follow-up talks, angered by U.S. actions soon after the 2005 deal under which it freezes Pyongyang's accounts at a Macau bank accusing it of money laundering. It stays away from the negotiating table for more than a year until Washington arranges for the release of the funds.
DEFIANT NUCLEAR TEST
North Korea sets off a nuclear device in October 2006, triggering U.N. Security Council sanctions. But the test also leads to a series of meetings between the U.S. and North Korea to try to devise a way for the North's return to the talks.
In 2007, a deal is reached at the talks to provide the North with a million tons of heavy fuel oil in return for steps by Pyongyang to shut down and seal its main Yongbyon nuclear plant that produces weapons-grade plutonium and to invite inspectors to oversee them.
TALKS BREAK DOWN
A round of the six-way talks ends in December 2008 with sharp disagreement on how to verify the North's steps to disable its nuclear program.
Following a long-range missile test in April 2009, the North declares dialogue with the United States over. In July, the North declares the six-party talks dead because it is no longer a forum of discussions on equal footing.
NORTH KOREA CALLS FOR RESUMPTION
Avoiding direct blame by the U.N. Security Council in July 2010 for the sinking of a South Korean navy ship earlier that year, the North says it is willing to return to nuclear talks.
DEATH OF KIM JONG-IL
North Korean leader Kim Jong-il dies in December, 2011 and is succeeded by his son, Kim Jong-un. U.S. envoy Glyn Davies holds talks in Pyongyang on February 23 and 24, 2012 in hopes the new leadership will make moves to curb its nuclear programs.