By Yoonjung Seo, Lucas Lilieholm and Mike Valerio, CNN

Seoul, South Korea (CNN) — New pictures of North Korean leader Kim Jong Un touring what state media said is a uranium enrichment facility have given an extremely rare glimpse inside the isolated nation’s closely guarded nuclear weapons program.

According to a report from Korean Central News Agency (KCNA) on Friday, Kim visited the facility – a bright, sterile warehouse filled with long rows of cylindrical machinery – which is used to produce weapons-grade nuclear material for the North’s growing arsenal.

The report comes as North Korea continues to ramp up its illegal nuclear weapons program and strengthens relations with Russia, deepening widespread concern in the West over the isolated nation’s direction under Kim.

The location and exact date of Kim’s visit to the site were not disclosed in the report, but the purpose of his inspection was clear, according to KCNA: to lay out a “long-term plan for increasing the production of weapon-grade nuclear materials.”

Experts say the images – which show Kim flanked by men in military uniforms and crisp white lab shirts – underscore North Korea’s growing confidence in its position as a nuclear power.

“Kim is exceptionally confident these days and he’s particularly interested in making sure that his calls for a massive increase in nuclear capabilities are not misinterpreted,” said Ankit Panda, Stanton Senior Fellow at the Carnegie Endowment for International Peace, adding “these disclosures lend credibility to North Korea’s plans and demonstrate that they’ve come a long way in their enrichment capabilities.”

It’s a theme the North Korean leader has touched on frequently in recent years, including this week.

In a speech celebrating the 76th anniversary of North Korea’s founding on Monday, Kim pledged to “exponentially” expand the regime’s nuclear arsenal, reiterating bellicose rhetoric he has used in the past.

During his visit to the purported enrichment facility, Kim expressed repeated satisfaction with the technical capabilities of North Korea’s nuclear sector and emphasized the need to increase the number of centrifuges for greater production, according to state media.

Park Won-gon, professor of North Korean Studies at Ewha Womans University in Seoul, said the timing of the disclosure is also important.

“By showing highly enriched uranium and production facilities, they are sending a message that the world must recognize North Korea as a nuclear state. By disclosing these facilities, Kim Jong Un is saying that denuclearization of North Korea is unrealistic,” he told CNN.

That stance is unlikely to be accepted by the US and its allies in the region.

In an interview with CNN on Tuesday, former US national security adviser Robert O’Brien said America and its partners should continue to work towards denuclearization of the Korean Peninsula.

The former Trump Administration official added it would be difficult for the US to accept North Korea as a nuclear power even if Pyongyang were to stop building new nuclear weapons. Such an agreement, he argued, could contribute to wider nuclear proliferation.

“To excuse the North Koreans and say, ‘It’s okay for North Korea to have a bomb,’ it’s pretty hard then to say, ‘Well, no, Iran can’t have a bomb, and Saudi Arabia can’t have a bomb to deter Iran,’” O’Brien said.

“It can’t just be that the bad guys can get the bomb with impunity.”

The carefully released pictures of the uranium enrichment facility comes at a time of heightened tensions between North Korea and the West, with the US and its allies accusing North Korea of providing substantial military aid to Russia’s war effort in Ukraine. Both Moscow and Pyongyang have denied North Korean arms exports, despite significant evidence of such transfers.

In June, the two autocratic nations pledged to use all available means to provide immediate military assistance in the event the other is attacked, according to a landmark defense pact agreed to during a visit by Russian President Vladimir Putin to Pyongyang.

Since the location of this facility was not revealed in the KCNA report, it’s unclear whether the images are from a site already known to international observers, such as the Yongbyon nuclear research facility, or something entirely new. North Korea is believed to have several sites for enriching uranium.

“I’m not sure we can establish the site from the images,” said Martyn Williams, a Senior Fellow at the Stimson Center, “but it’s certainly the first time we’ve seen this set up and in this level of detail.”