SEOUL: North Korean leader Kim Jong-un has called for increasing the number of centrifuges for uranium enrichment in order to expand its nuclear weapons for self-defense, the state media said Friday. Kim made the call during a visit to the Nuclear Weapons Institute and the "production base of weapon-grade nuclear materials," according to the Korean Central News Agency (KCNA). The dispatch did not release the location of the facility or date of the visit. "He went round the control room of the uranium enrichment base to learn about the overall operation of the production lines," the KCNA said, adding that Kim expressed great satisfaction after being briefed that the "base is dynamically producing nuclear materials." The North Korean leader has stressed the need to further augment the number of centrifuges in order to exponentially increase the nuclear weapons for self-defence true to the Party's line of building up nuclear armed forces, the report said. It marks the first time North Korea has publicly rev ealed details of its uranium enrichment facility. A uranium enrichment facility is used to produce highly enriched uranium (HEU) by placing uranium in centrifuges and spinning it at high speeds. HEU is essential for the manufacturing of nuclear warheads, along with plutonium. South Korean and US intelligence agencies believe North Korea operates uranium enrichment facilities at the Kangson nuclear complex near Pyongyang and at the Yongbyon nuclear site. Source: Philippines News agency