North Korea continues to expand operations at the Yongbyon light water reactor, the head of the UN’s nuclear watchdog said on Thursday.

International Atomic Energy Agency (IAEA) chief Yukiya Amano said work continued at the North Korean facility during a statement to the group’s board of governors.

“At the Light Water Reactor, the Agency also observed activities consistent with the fabrication of reactor components and the possible transfer of these components into the reactor building,” Amano said.

“At Yongbyon, further activities were observed near the Kuryong River. These may be related to changes to the cooling infrastructure for the 5MW(e) reactor