North Korea appears to have resumed construction of a second reactor at its Yongbyon nuclear site after a long period of inactivity.

According to CNN and other foreign media outlets, new satellite imagery by Maxar showed the North has restarted construction of the reactor recently, and the United States government is closely monitoring the situation.

Experts reportedly said that it is hard to predict when the construction would be completed, but the capacity of the reactor would be around 50 megawatts.

According to CNN, the reactor is about ten times larger than the existing reactor at Yongyon, which has been operating since the late 1980s.

Jeffery Lewis, a weapons expert at the U.S. Middlebury Institute of International Studies, reportedly said the reactor, if completed, could allow the North to increase its production of plutonium for nuclear weapons by ten times.