SEOUL, South Korea, Sept 14, (AP): North Korea offered a rare glimpse into a secretive facility to produce weapons-grade uranium as state media reported Friday that leader Kim Jong Un visited the area and called for stronger efforts to "exponentially” increase the number of his nuclear weapons. It’s unclear if the site is at the North's main Yongbyon nuclear complex, but it's the North's first disclosure of a uranium-enrichment facility since it showed one at Yongbyon to visiting American scholars in 2010.

While the latest unveiling is likely an attempt to apply more pressure on the US and its allies, the images North Korea's media released of the area could provide outsiders with a valuable source of information for estimating the amount of nuclear ingredients that North Korea has produced. During a visit to the Nuclear Weapons Institute and the production base of weapon-grade nuclear materials, Kim expressed "great satisfaction repeatedly over the wonderful technical force of the nuclear power field” held by North Korea, the official Korean Central News Agency reported.

KCNA said that Kim went around the control room of the uranium enrichment base and a construction site that would expand its capacity for producing nuclear weapons. North Korean state media photos showed Kim being briefed by scientists while walking along long lines of tall gray tubes, but KCNA didn’t say when Kim visited the facilities and where they are located.

KCNA said Kim stressed the need to further augment the number of centrifuges to "exponentially increase the nuclear weapons for self-defense,” a goal he has repeatedly stated in recent years. It said Kim ordered officials to push forward the introduction of a new-type centrifuge, which has reached its completion stage. Kim said North Korea needs greater defense and preemptive attack capabilities because "anti-(North Korea) nuclear threats perpetrated by the U.S. imperialists-led vassal forces have become more undisguised and crossed the red-line,” KCNA said.