North Korea has revealed the first images of a uranium enrichment facility aimed at producing weapons-grade fuel for its nuclear bombs.

The regime argues that its expanding arsenal of nuclear weapons and ballistic missiles is crucial for defending against perceived threats from the U.S. and its allies, who opposed North Korea during the Korean War (1950-1953).

Pyongyang often touts these weapons as a matter of national prestige and proof of the country's power.

North Korea has the capability to deliver nuclear weapons using a variety of land-based missile systems, including intercontinental ballistic missiles (ICBMs) with ranges capable of targeting the continental United States, according to the U.S.-based Arms Control Association.

Critics, including those in Washington and Seoul, say these weapons are destabilizing, pose a threat to North Korea's neighbors, and divert resources away from the country's impoverished citizens.

The United Nations Security Council has passed multiple resolutions banning North Korea's nuclear weapons and ballistic missile development. However, council members Russia and China have blocked new sanctions and called for existing ones to be rolled back.

How many nuclear weapons does North Korea have?

State media have shown photos of various types of warheads, but North Korea has never disclosed the number of weapons it possesses. Analysts and foreign intelligence agencies have only rough estimates.

In July, a report by the Federation of American Scientists concluded that the country may have produced enough fissile material to build up to 90 nuclear warheads, but it has likely assembled closer to 50.

Lee Sang-kyu, a nuclear engineering expert at South Korea's Korea Institute for Defense Analysis, estimates North Korea has 80-90 nuclear warheads made of uranium and plutonium, with that number expected to rise to 166 by 2030.

How does North Korea build its nuclear weapons?

North Korea has facilities scattered across the country contributing to its nuclear program, including mines for raw uranium, enrichment facilities, nuclear reactors for turning uranium and plutonium into bomb fuel, and weapons assembly plants.

The Yongbyon Nuclear Scientific Research Center, built in the late 1950s with Soviet aid, houses at least three reactors, which North Korea says are intended for electricity production.

It also has a fuel fabrication facility and a plutonium reprocessing plant where weapons-grade materials can be extracted from spent fuel rods, according to the Nuclear Threat Initiative (NTI), a Washington-based think tank.

The enrichment facility shown on Friday could be located at Yongbyon or at another site. North Korea is also believed to have more centrifuges, including at a site in Kangson.

Where does North Korea test its weapons?

The Punggye-ri Nuclear Test Site, located in a mountainous region in the far northeast of the country, about 100 kilometers (62 miles) from the border with China, has been the site of all six of North Korea’s nuclear tests: in 2006, 2009, 2013, January 2016, September 2016 and September 2017.

Analysts questioned North Korea’s claim that the January 2016 blast was its first thermonuclear bomb but believe a thermonuclear weapon was likely tested in 2017 in an explosion much larger than previous tests.

All the tests were conducted in tunnels dug deep under the mountains. There are three visible entrances known as the South Portal, East Portal, and West Portal.

The entrances to these tunnels were demolished in front of a small group of foreign media invited to view the destruction when North Korea closed the site in 2018, declaring a self-imposed moratorium on nuclear weapons tests.

Kim Jong Un has since said he no longer feels bound by the moratorium, with denuclearization talks stalled since 2019.

In 2022, satellite imagery showed North Korea working to restore some of the tunnels, raising the prospect of new tests.