Washington (CNN) What first appeared to be a gesture indicating North Korea might be willing to dismantle its nuclear weapons program appears to have been little more than a propaganda effort for the world's cameras.

Billing it as an exercise in transparency, North Korean officials invited international journalists to witness the detonation of their underground nuclear test tunnels at Punggye-ri -- but intelligence has increasingly shown that the public spectacle may have amounted to little more than a show, according to US intelligence and international arms control officials.

A CNN crew at the remote mountain site in the country's north witnessed explosions at nuclear tunnels 2, 3 and 4 from observation decks about 500 meters (547 yards) away. They were among two dozen journalists invited into the country to observe the apparent destruction of the site.

Hours later, the White House canceled a planned meeting between North Korean leader Kim Jong Un and US President Donald Trump, but Trump announced Friday that the June 12 summit is back on despite no further demonstrations of goodwill by Pyongyang.

In this Thursday, May 24, 2018 photo, The fourth tunnel of North Korea's nuclear test site is blown up in Punggye-ri, North Korea. North Korean leader Kim Jong Un made good on his promise to demolish his country's nuclear test site, which was formally closed in a series of huge explosions Thursday as a group of foreign journalists looked on. (Korea Pool/Yonhap via AP)

No weapons inspectors or nonproliferation experts were invited to witness the detonation, and now initial assessments indicate that the show was essentially a charade.

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