A US Intelligence Chief says North Korea has restarted its plutonium reactor and could start recovering spent fuel in weeks.
James Clapper also said that North Korea had taken steps towards making an intercontinental ballistic missile system.
It came days after North Korea launched a long-range rocket, which critics said is a test of banned missile technology.
The Hermit State announced its intention to restart the Yongbyon facility in March 2013, but reports had recently claimed it was running at reduced power.
The plant is capable of making weapons-grade plutonium at a rate of just under 6 kilograms per year, enough to make one nuclear bomb.
“We assess that North Korea had followed through on its announcement by expanding its Yongbyon enrichment facility and restarting the plutonium production reactor,” Clapper said.
He added that the reactor had now been operating for long enough to start recovery of spent fuel within a matter of weeks to months.
North Korea had also expanded the size and sophistication of its ballistic missile forces including intercontinental missiles.
Last September, Pyongyang said its main nuclear facility at Yongbyon had resumed normal operations.
The reactor there had been the source of plutonium for its nuclear weapons programme. North Korea carried out its fourth nuclear test in January.
