The US has asked the North Korean regime to allow observers to witness the dismantling of the Sohae missile testing base, US Secretary of State Mike Pompeo has said.

When reporters in Palo Alto, California, asked Pompeo on Tuesday what further steps were needed by North Korea, the secretary of state said: “They need to completely, fully denuclearize. That’s the steps that Kim Jong-un (North Korean leader) committed to.”

Satellite photos published on Tuesday on the specialised website 38 North show that Pyongyang has begun dismantling the Sohae base, where the regime of Kim Jong-un builds engines for intercontinental ballistic missiles that supposedly have the range to hit US territory, Efe news reported.

The process of dismantling the base has been proceeding without the presence of international observers, according to various media reports.

When asked about the images of the military base, Pompeo said that North Korea’s actions are “consistent” with the “commitment” Kim made to President Donald Trump during their historic June 12 summit in Singapore.

After that meeting, Trump said that Kim had promised to very quickly dismantle a missile engine testing base, although he did not specify which base that might be.

US government officials later said that Sohae – in northwestern North Korea – was the base that would be closed.

At their summit, the two leaders signed a declaration opening the door to North Korea’s denuclearisation in exchange for US guarantees regarding the Pyongyang regime’s survival, but it did not specify the mechanisms or any concrete time periods for attaining that objective.

Skepticism over North Korea’s willingness to denuclearize has grown since US media reported in late June – citing national intelligence sources – that Pyongyang has continued to enrich uranium after the summit and that it was trying to hide a large part of its arsenal and other military assets from the US.