North Korea's nuclear threat: What we know
North Korea said Friday it tested a nuclear warhead designed to be mounted on a ballistic missile, promising to hit back at its enemies if provoked.
Here's what we know about the reclusive country's nuclear weapons program:
Nuclear tests: Two this year, in September and January. Others in 2013, 2009 and 2006.
Nuclear arsenal: Estimates vary from eight warheads (the Arms Control Association, Aug. 2016) to 10-16 (Institute for Science and International Security, 2015).
Chinese nuclear experts told U.S. counterparts in 2015 that North Korea had up to 20 warheads and could double that number in the following year.
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Delivery systems:
— Taepodong-3, Ballistic/ Space Launch Vehicle, maximum payload: 2,000 lb., range: 8,000+ miles (capable of reaching continental U.S.)
— Taepodong-2 ballistic missile, maximum payload: 225 lb., range: 6,000 miles
— Taepodong-1 ballistic missile, maximum payload: 90 lb., range: 1,800 miles
— Musudan ballistic missile, payload: 225 lb., range: 2,500 miles
— Nodong ballistic missile, payload: 320 lb., range: 900 miles
Background: North Korea's interest in a nuclear weapons program dates to the end of World War II. The United States has been negotiating with North Korea to limit its nuclear program in six-party talks together with South Korea, China, Japan and Russia. North Korea agreed to shut down its nuclear program in 2007 in exchange for humanitarian aid.
A look at North Korea's 5 nuclear tests
It withdrew from the talks in 2009, in response to international condemnation of a satellite launch that analysts said masked a banned ballistic missile test. The United Nations Security Council passed five major resolutions since 2006 that impose and strengthen sanctions on North Korea for continuing to develop its nuclear weapons program.
International law: North Korea withdrew from the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 2003 and is not party to the Comprehensive Nuclear-Test-Ban Treaty or a member of the Missile Technology Control Regime. It also has shunned the Chemical Weapons Convention, and is believed to possess 2,500-5,000 metric tons of chemical weapons.
Sources: Nuclear Threat Initiative, Institute for Science and International Security, Arms Control Association