VIENNA, Aug. 30 — Iran is expanding its nuclear program in defiance of United Nations’ resolutions, even as it has promised to answer questions about an array of suspicious nuclear activities in the past, the International Atomic Energy Agency said Thursday.
The assessment by the nuclear agency states that Iran is now simultaneously operating nearly 2,000 centrifuges, the machines that produce enriched uranium, at its vast underground facility at Natanz, an increase of several hundred machines from three months ago. More than 650 additional centrifuges are being tested or are under construction, the agency said.

