In Another Threat, Iran Warns It May Ban All Inspectors

VIENNA, Feb. 2 — Iran formally notified the International Atomic Energy Agency on Thursday that it would end all "voluntary" nuclear cooperation with the agency if, as expected, its 35-country board referred Iran's nuclear activity case to the United Nations Security Council.

If the threat, in a letter from Ali Larijani, Iran's chief nuclear negotiator, to Mohamed ElBaradei, the director of the agency, is carried out, inspectors will no longer be permitted to conduct spot inspections and will lose access to crucial sites, including several military areas that have aroused the agency's suspicions.

In addition, Iran has said it will resume its program to build 50,000 centrifuges at Natanz and begin full-scale production of enriched uranium, which can be used to produce electricity or to build nuclear bombs.