North and South Korea recently began engaging in their first high level diplomatic talks in over two years, resulting in some tentative steps toward improved relations, including an agreement to march together at the upcoming Winter Olympics and even combine women’s ice hockey teams for the games. However, while the international media has focused their attention on the possibility for peace, Kim Jong Un’s regime has continued to move toward more nuclear and ballistic missile tests, satellite imagery has confirmed.

Images taken by commercial satellite on January 6th, and secured by the North Korea watchdog 38 North, show what would appear to be continued work on a second submersible barge used specifically for undersea ballistic missile test launches. The barge was seen in previous satellite photographs at a nearby fitting-out dock, but the new shots clearly show a floating crane moored alongside with the boom extended over the barge, seeming to indicate continued work on the platform.

Once completed, the barge will serve as a test bed for submersible ballistic missile launches – a tricky endeavor, as a failure to clear the surface of the water could result in the missile falling back onto the submarine launching it, potentially detonating the nuclear warhead. North Korea has been working on an operational ballistic missile submarine, which when completed and coupled with missiles developed using this barge platform, will provide a second leg to North Korea’s nuclear deterrent enterprise – or offer a submersible platform from which to launch a first strike.

But further ballistic missile testing isn’t all Kim Jong Un’s regime is continuing to pursue, despite seemingly warming relations with their neighbor to the south and tightening sanctions imposed by the United Nations. Other satellite images taken throughout the last few weeks of December also show significant tunneling activity in Punggye-ri Nuclear Test Site buried beneath Mount Mantap.

The North Portal of the test site, where at least five of North Korea’s six nuclear weapons tests were conducted, remains dormant following a tunnel collapse that killed an estimated 200 people, caused by the detonation of the nation’s first ever thermonuclear device. The test caused a 6.1 magnitude earthquake felt for hundreds of miles, and prompted serious questions regarding the stability of the mountain the complex lies beneath.

However, mining carts and personnel could clearly be seen working in the West Portal, where it appears an effort is underway to establish a new area for further nuclear weapons testing. There is also a growing pile of soil seen outside the entrance to the tunnels, clearly indicating ongoing excavation inside.

North Korea has repeatedly stated that they are not willing to address their nuclear and ballistic missile programs in their talks with South Korea, though the United States has made it clear that denuclearizing is a requisite for peace.