North Korea has released images of its uranium enrichment facility for the first time, showing leader Kim Jong-un touring a nuclear facility.

The state media reported on Friday that the North Korean leader called for increasing the number of centrifuges for uranium enrichment to increase the nation’s nuclear arsenal for self-defense.

The country, which conducted its first nuclear test in 2006, has never publicly disclosed details of its uranium enrichment facility.

Such facilities produce highly enriched uranium by spinning the original material in centrifuges at high speeds.

Kim toured the Nuclear Weapons Institute and the “production base of weapon-grade nuclear materials,” according to the Korean Central News Agency (KCNA).

The KCNA did not give the location of the facility or the date of the visit.

Kim “stressed the need to further augment the number of centrifuges in order to exponentially increase the nuclear weapons for self-defense,” the KCNA reported, publishing images of Kim inspecting rows of centrifuges.

Kim “acquainted himself with the production of nuclear warheads and current nuclear materials,” the report said.

“He went round the control room of the uranium enrichment base to learn about the overall operation of the production lines,” the KCNA said.

The North Korean leader was briefed about the facility “dynamically producing nuclear materials by studying, developing and introducing all the system elements including centrifugal separators,” the KCNA said.

“When he personally went round the worksite, he said that he felt strong to see the worksite,” the state media said.

Kim urged the facility to “push forward the introduction of a new-type centrifuge… so as to further strengthen the foundation for producing weapon-grade nuclear materials.”

He also “stressed the need to set a higher long-term goal in producing nuclear materials necessary,” added KCNA.

Pyongyang, which has been under harsh sanctions by the United States and the United Nations Security Council for years over its nuclear and ballistic missile programs, says such military maneuvers amount to a rehearsal for invasion.

Kim has repeatedly said that Pyongyang is strengthening its armed forces to confront the US and its regional allies in a war that could “break out at any time” on the Korean Peninsula.