New | North Korea restarted its Yongbyon nuclear reactor, says US intelligence official

North Korea has followed through on its threat to advance its nuclear weapons programme, the top US intelligence official said on Wednesday, while a research institute pointed to signs the communist country is preparing to launch bigger rockets.

Those developments will add to the international concern about the intentions of young leader Kim Jong-un, amid scant sign that negotiations to curb North Korea’s nuclear ambitions will resume any time soon.

In written testimony to the Senate Intelligence Committee, Director of National Intelligence James Clapper said North Korea has expanded the size of the uranium enrichment facility at the Yongbyon nuclear complex and restarted a reactor that was used for plutonium production before it was shut down in 2007.

Those findings concur with assessments published last summer by think tanks that monitor North Korea’s nuclear programme using commercial satellite imagery. South Korean intelligence also has said the reactor has restarted.

“North Korea’s nuclear weapons and missile programmes pose a serious threat to the United States and to the security environment in East Asia,” Clapper said. He said the North is committed to developing a long-range missile that can threaten the US

North Korea announced its intention to “adjust and alter” its existing nuclear facilities after an underground, atomic test explosion last February, backtracking from denuclearization commitments. That announcement came during a period of high tension when the North issued threats of a nuclear strike on the United States.

Tensions have eased some since then, and the North says it wants to improve ties with South Korea. The North has said it is willing to resume, without preconditions, the six-nation aid-for-disarmament talks from which it withdrew in 2009.