The U.N. nuclear watchdog said it has seen releases of steam and water indicating that North Korea may be operating a reactor, in the latest update on a plant that experts say could make plutonium for atomic bombs.
North Korea announced in April of last year that it would revive its aged 5-megawatt research reactor at the Yongbyon nuclear complex, saying it was seeking a deterrent capacity.
The isolated and poverty-stricken state defends its nuclear program as a "treasured sword" to counter what it sees as U.S.-led hostility.