The International Atomic Energy Agency has expressed serious concern over signs that North Korea has resumed the operation of a nuclear reactor in Nyongbyon.
The UN's nuclear agency released its latest report, dated Friday, about North Korea's nuclear development programs.
The agency wrote that, "since early July 2021, there have been indications, including the discharge of cooling water, consistent with the operation of the reactor."
It added that there had been no such indications from early December 2018 to the beginning of July 2021.
It also pointed out that a steam plant at the Nyongbyon nuclear site had operated for approximately five months, from mid-February 2021 to early July 2021.
It said the five-month period is consistent with the time required to reprocess spent fuel.
The IAEA said the continuation of North Korea's nuclear program is a clear violation of UN Security Council resolutions and is deeply regrettable.