North Korea Nuclear Timeline Fast Facts

(CNN)Here is a look at North Korea's nuclear capabilities and weapons program history.

1985
North Korea joins the Nuclear Non-Proliferation Treaty (NPT).
    1993
    International Atomic Energy Agency (IAEA)
    charges that North Korea is violating the NPT and demands that inspectors be given access to two nuclear waste storage sites.
    North Korea threatens to quit the Nuclear Nonproliferation Treaty amid suspicions that it is developing nuclear weapons. It ultimately does not quit the program but agrees to inspections in 1994.
    1994
    North Korea and US sign an agreement. North Korea pledges to freeze and eventually dismantle its nuclear weapons program in exchange for international aid to build two power-producing nuclear reactors.
    1998
    November 17 -
    The US and North Korea hold the first round of high-level talks in Pyongyang over North Korea's suspected construction of an underground nuclear facility. The United States demands inspections.
    1999
    February 27-March 16 -
    During a fourth round of talks, North Korea allows US access to the site in exchange for US aid in increasing North Korean potato yields. US inspectors find no evidence of any nuclear activity during a visit to site in May.
    September 17 - President Bill Clinton agrees to ease economic sanctions against North Korea.
    December - A US-led international consortium signs a $4.6 billion contract to build two nuclear reactors in North Korea.
    2000
    July -
    North Korea threatens to restart its nuclear program if the US does not compensate it for the loss of electricity caused by delays in building nuclear power plants.
    2001
    June -
    North Korea warns it will drop its moratorium against testing missiles if the US does not pursue normalized relations with North Korea. It also says it will restart its nuclear program if there is not more progress on two US-sponsored nuclear power plants being built in North Korea.
    2002
    January 29 - President George W. Bush labels North Korea, Iran and Iraq an "axis of evil" in his State of the Union address. "By seeking weapons of mass destruction, these regimes pose a grave and growing danger," he says.
    October 4 - US officials, in closed talks, confront North Korea with evidence that they are operating a nuclear weapons program in violation of the 1994 nuclear agreement. North Korea admits that is has been operating the facility in violation of the agreement. The information is not made public.
    October 16 - The Bush Administration first reveals that North Korea has admitted operating a secret nuclear weapons program in violation of the 1994 agreement. It is unclear whether Pyongyang has any completed nuclear weapons.
    December 22 - North Korea says it has begun removing IAEA monitoring equipment from nuclear facilities.
    December 31 - North Korea expels IAEA inspectors.
    February 5 - North Korea's official news agency says the nation has reactivated its nuclear power facilities.
    February 26 - The United States confirms North Korea has reactivated its five-megawatt nuclear reactor at Yongbyon.
    April 23 - Declares it has nuclear weapons.
    August 27 - The US, North Korea, South Korea, China, Japan and Russia take part in talks about the crisis in North Korea.
    2004
    February 24-28 -
    The US, North Korea, South Korea, China, Japan and Russia meet in Beijing, China for more talks. The summit closes with no major progress but with an agreement for more talks.
    June - The six nations meet again in Beijing for more talks.
    August - North Korea offers to freeze its nuclear program in exchange for aid, easing of sanctions and being removed from the US' list of state sponsors of terrorism. The US wants North Korea to disclose all nuclear activities and allow inspections.
    2005
    February 10 -
    North Korea drops out of six-party nuclear talks and says it will bolster its nuclear weapons arsenal. North Korea insists on a bilateral non-aggression pact with the US before it will consider dismantling its nuclear program. The US insists Pyongyang must first agree to permanently and verifiably dismantle its nuclear weapons program before it will grant any incentives.
    August 7 - After meeting for 13 straight days, diplomats from the United States, North Korea and four other Asia-region powers decide to take a recess from talks aimed at getting North Korea to dismantle its nuclear program.
    September 13 - The six-party talks resume in Beijing.
    September 19 - North Korea agrees to give up its entire nuclear program, including weapons, a joint statement from six-party nuclear arms talks in Beijing said. "The Democratic People's Republic of Korea (North Korea) committed to abandoning all nuclear weapons and existing nuclear programs and returning at an early date to the treaty on the nonproliferation of nuclear weapons (NPT) and to IAEA (International Atomic Energy Agency) safeguards."
    -- In exchange, the US, China, Japan, Russian and South Korea have "stated their willingness" to provide energy assistance to North Korea, as well as promote economic cooperation.
    -- North Korean officials later state that their country would begin dismantling its nuclear program only if the US provides a light-water reactor for civilian power -- threatening the day-old agreement, "Without this physical guarantee of the (light-water reactor), our position is not to even dream of us giving up our nuclear deterrence."
    2006
    July 15 -
    The UN Security Council unanimously passes a resolution demanding that North Korea suspend its missile program. The North Korean ambassador immediately rejects the resolution.
    October 9 - North Korea claims to have successfully tested its first nuclear weapon. The supposed test is conducted at an underground facility in Hwaderi near Kilju city. Though the nature of the blast as nuclear remains unconfirmed, South Korea's geology research center detects an artificial earthquake in the region of the test, and world leaders condemn North Korea's actions
    October 14 - The UN Security Council approves a resolution imposing sanctions against North Korea, restricting military and luxury goods trade and requiring an end to nuclear and ballistic missile tests.
    October 16 - An analysis of air samples collected on October 11, 2006 detects radioactive debris, confirming North Korea's nuclear test.
    2007
    February 13 -
    North Korea agrees to close its main nuclear reactor in exchange for an aid package worth $400 million.
    March 5-6 - US Assistant Secretary of State Christopher Hill meets with Vice Foreign Minister Kim Kye Gwan to discuss North Korea's nuclear program.
    March - During six-party talks, the US agrees to release approximately $25 million of North Korean funds frozen at a Macao bank, a sticking point in the negotiations. The actual release of funds does not occur until June.
    June 25 - After spending two days in Pyongyang meeting with North Korea's nuclear negotiator, the US envoy to North Korea, Chris Hill, says that North Korea has reaffirmed its commitment to the nuclear disarmament agreement reached in February.
    September 2 - US Assistant Secretary of State Christopher Hill announces that after talks in Geneva between US and North Korean officials, North Korea has agreed to fully declare and disable its nuclear programs by the end of 2007.
    September 30 - At six-party talks in Beijing, North Korea signs an agreement stating it will begin disabling its nuclear weapons facilities. North Korea also agrees to include a US team of technical experts in the disabling activities.
    October 2 - South Korean President Roh Moo-hyun becomes the first South Korean leader to walk across the Demilitarized Zone separating North and South Korea on his way to a three-day summit with North Korean leader Kim Jong Il.
    October 4 - North Korean leader Kim Jong Il and South Korean President Roh Moo-hyun sign an eight-point agreement in Pyongyang; among other things, it calls for a smooth implementation of the six-party agreements to shut down of North Korea's nuclear facilities and the replacement of North and South Korea's current armistice agreement with a permanent peace.
    November 14-16 - North Korean Prime Minister Kim Yong Il and South Korean Prime Minister Han Duck-soo meet in Seoul, South Korea. At the end of the summit, they announce a number of economic projects including cross-border cargo train services, road repairs, and construction of a new industrial complex near Haeju, North Korea.
    December 31 - North Korea misses a deadline to declare all its nuclear programs.
    2008
    January 4 -
    The North Korean Foreign Ministry states, via broadcast message, that North Korea had already provided enough explanation to meet the 12/31/2007 deadline, and that it had provided that information in a report presented to the US in November. Members of the six party talks dispute this claim.
    February 21 - After meeting with North Korean Foreign Minister Kim Kye Gwan, South Korean envoy Chun Yung Woo states that North Korea still plans to meet the obligations it agreed to during six-party talks in 2007.
    May 8 - An official with the US State Department announces that North Korea has handed over thousands of documents pertaining to its nuclear activities, especially related to its production of plutonium, to visiting US official Sohn Kim.
    June 27 - North Korea destroys a water cooling tower at the Yongbyon facility, where officials now acknowledge they extracted plutonium to build nuclear weapons. The massive implosion is intended to be a powerful public symbol of a move to end nuclear activities by the communist nation.
    September 24 - At the request of North Korea, the IAEA removes surveillance equipment and seals from the Yongbyon nuclear facility, a move toward possibly restarting its suspended nuclear program.
    October 11 - US State Department spokesman Sean McCormack announces that North Korea has been removed from the US list of states that sponsor terrorism.
    October 10-17 - In response to the US move, North Korea replaces the seals and surveillance equipment at its Yongbyon nuclear facility.
    December 8-11 - Another round of six-party talks is held in Beijing, China. The talks break down over North Korea's refusal to allow international inspectors unfettered access to suspected nuclear sites.
    2009
    January -
    United States scholar Selig Harrison meets with senior officials in North Korea. After the meeting he reports that the officials have claimed that North Korea has weaponized most of its plutonium stockpile. The amount of weaponized plutonium is allegedly enough for four to five nuclear bombs.
    April 25 - North Korea announces it has begun reprocessing spent fuel rods.
    May 25 - North Korea announces it has conducted its second nuclear test shortly after the US Geological Survey reports a magnitude 4.7 seismic disturbance at the site of North Korea's first nuclear test.
    June 12 - The UN Security Council approves Resolution 1874, condemning North Korea's May 25th nuclear test. The UN also imposes new sanctions, banning the sale of most arms to or from North Korea.
    November 3 - North Korea's state-run news agency reports that the reprocessing of 8,000 spent nuclear fuel rods has been completed. The reprocessing garnered enough weapons-grade plutonium for one to two nuclear bombs.
    2010
    November 20 -
    According to a report by Stanford University professor Siegfried Hecker, North Korea has a new nuclear enrichment facility composed of 2,000 centrifuges. Hecker was given unprecedented access to North Korea's facility and documents.
    2011
    October 24-25 -
    US officials meet with a North Korean delegation in Geneva, Switzerland, in an effort to restart the six-party nuclear arms talks that broke down in 2008.
    December 15 - US and North Korean officials meet in Beijing to discuss possible food assistance to North Korea in exchange for the suspension of North Korea's uranium enrichment program.
    2012
    January 11 -
    North Korea indicates that it is open to further discussions with the US over suspending its uranium enrichment program in exchange for food aid, an agreement that seemed close to realization before Kim Jong Il's death on December 17, 2011.
    May 24 - A spokesperson for South Korea's Defense Ministry says that based on analysis of commercial satellite images at North Korea's nuclear test site, North Korea appears ready to carry out a nuclear test at any time.
    2013
    January 24 -
    North Korea's National Defense Commission says it will continue nuclear testing and long-range rocket launches, all of which are a part of an "upcoming all-out action" aimed at the United States, "the sworn enemy of the Korean people." Two days prior to this statement, the United Nations Security Council condemned a recent rocket launch by North Korea and expanded sanctions.
    February 12 - Conducts its third nuclear test. This is the first nuclear test carried out under leader Kim Jong Un.
    2014
    October 2 -
    A senior North Korean envoy says the country is ready to resume the six-party talks regarding its nuclear program. However, referring to joint exercises by South Korea and the United States, So Se Pyong, North Korea's ambassador to the UN, said the DPRK "have to be alert also, we have to be prepared to make counter measures against military exercise which are against us."
    2015
    May 6 -
    Park Yong Chol, deputy director of the DPRK Institute for Research into National Reunification, tells CNN in an exclusive interview that his country has the missile capability to strike mainland United States and would do so if the US "forced their hand."
    May 20 - North Korea says that it has the ability to miniaturize nuclear weapons, a key step toward building nuclear missiles. A US National Security Council spokesman responds that the US does not think the North Koreans have that capability.
    December 12 - North Korea state media says the country has added the hydrogen bomb to its arsenal, a development that, if true, would represent a major leap in its nuclear weapons capabilities. A hydrogen bomb can be hundreds of times more powerful than an atomic bomb.
    2016
    January 6 -
    North Korea says it has successfully conducted a hydrogen bomb test.
    September 9 - North Korea claims to have detonated a nuclear warhead. According to South Korea's Meteorological Administration, the blast is estimated to have the explosive power of 10 kilotons -- twice the power of the country's last test. The US Geological Survey (USGS) reported a 5.3 magnitude earthquake in North Korea, but later termed it an explosion.