The International Atomic Energy Agency says activity has been observed at a North Korean nuclear reactor, consistent with an effort to restart it.
IAEA chief Yukiya Amano told the agency's 35-member board Thursday that North Korea's Yongbyon nuclear complex appears to have re-started its reactor. But the agency says without access to the site, IAEA inspectors cannot draw a definite conclusion.
North Korea destroyed the cooling tower at Yongbyon in 2008 as a confidence-building measure in talks with South Korea, China, the United States, Japan, and Russia.
But in September, a U.S. research institute said satellite imagery of the site showed activity that could mean North Korea is reviving the reactor.