There are no indications that North Korea has ceased its nuclear development at several key sites, the UN’s International Atomic Energy Agency (IAEA) said in report published on Monday.

The IAEA came to the conclusion as part of its regular analysis of the DPRK’s nuclear weapons development programs, following the creation of a new North Korea-focused executive group formed last year to help improve monitoring.

“The continuation and further development of the DPRK’s nuclear programme and related statements by the DPRK are a cause for grave concern,” the IAEA said in the report.

The group noted that ongoing activities at Yongbyon Experimental