[8][9] On 6 January 2016, North Korean state media announced a fourth nuclear test had been carried out successfully at the location using a hydrogen bomb.

[10] Satellite imagery captured for monitoring website 38 North between January and April 2017 suggested that a sixth nuclear test was being prepared at the site, which was detonated on 3 September 2017.

[14] A 17 October 2017 study published by the US-Korea Institute at Johns Hopkins University suggested the most recent test had caused "substantial damage to the existing tunnel network under Mount Mantap".

[22] On 24 May 2018 foreign journalists reported that tunnels in the Punggye-ri nuclear test site had been destroyed by the North Korean government in a move to reduce regional tensions.

Additionally, the majority of the administrative and support facilities along Punggye-ri's 17-km-long complex were not demolished,[24][25] and caretaker activities have been noted as recently as 25 November 2020.

[26] David Albright of the Institute for Science and International Security noted: North Korea's action is better than a freeze and represents a disabling of the test site.

And two of the portals (numbers 3 and 4, using North Korean nomenclature) were apparently intact and usable for further nuclear explosions prior to the dismantling steps conducted.