While the future of talks between the United States and North Korea remains uncertain, satellite imagery of a North Korean nuclear complex has revealed the existence of two secret underground facilities.

The Yongbyon Nuclear Scientific Research Center, approximately 60 miles north of Pyongyang, has long been suspected of having such facilities, but the identification of tunnel entrances and soil piles offer proof of their existence.

"While it is impossible to remotely discern their purposes, their location within Yongbyon’s security perimeter and subsequent camouflaging qualify them as subjects of interest for future inspection teams," analysts with 38 North, a website focused on North Korea, said in a report.

There is speculation that the underground facilities house uranium enrichment centers. Experts have long believed North Korea has uranium enrichment capabilities in addition to the declared Yongbyon facility, which produced nuclear material for six of the Kim regime's weapons tests. This speculation began in 2013, when a North Korean defector sketched out the facility and possible underground areas that were used to hide "materials and laboratory testing equipment and important systems" prior to international inspections.

Analysts with the Center for Strategic and International Studies revealed the existence of another secret facility, known as the Kumchon-ni missile operating base, earlier this month. The base is believed to be tasked with striking targets in southern Japan and parts of South Korea in wartime.

CSIS exposed an additional North Korean ballistic missile base in January. Located 160 miles northwest of Seoul, South Korea, it is believed to be the headquarters of the Kim regime's strategic missile force.

"While diplomacy is critical, and should be the primary way to resolve the North Korean nuclear problem, any future agreement must take account of all of the operational missile base facilities that are a threat to U.S. and South Korean security," the CSIS report said.

Despite the talks that stalled earlier this year, President Trump on Friday touted his relationship with North Korean dictator Kim Jong Un.

"I think the best thing that’s happened to this country is the fact that, at least for three years — the fact that I have a very good relationship with Kim Jong Un," Trump told reporters.

The president was skeptical, however, that negotiations with Kim might yield success.

"We’ll see what happens. It might work out, it might not work out. I’m not saying it will. But in the meantime, he hasn’t been testing any nuclear," he said.