The officials told the Los Angeles Times they might agree to let Tehran continue enriching uranium up to concentrations of 5% if the Iranian government agreed to unrestricted inspections, and strict oversight and safeguards that the United Nations long has demanded.

Iran has begun enriching small amounts of uranium to 20% purity in February 2010 for what it contends are peaceful purposes, although most of its stockpile is purified at lower levels. Uranium can be used as bomb fuel at about 90% enrichment.