Pyongyang revealed a uranium enrichment facility for the first time today.

KCNA reported that North Korean leader Kim Jong-un visited the Nuclear Weapons Institute and the “base for the production of weapons-grade nuclear materials,” but the location of the facility and the date of the visit were not disclosed.

Kim called for increasing the number of uranium enrichment centrifuges to boost the country’s nuclear arsenal for self-defense.

The agency said Kim toured the control room of the uranium enrichment base to familiarize himself with the general operation of the production lines and expressed great satisfaction after being informed that “the base is dynamically producing nuclear materials.”

This is the first time North Korea has publicly disclosed details of the uranium enrichment facility.