NEW : The U.S. says the enrichment is ` ` further escalation '' by Iran . The CIA confirms uranium production has begun at the Fordo plant . Iran says its nuclear program has a medical purpose , a semi - official newspaper reports . Iran needs to reduce uranium to 20 % for radioisotopes to treat cancer , Kayhan reports .
NEW : The U.S. says the enrichment is `` further escalation '' by Iran . The IAEA confirms uranium enrichment has begun at the Fordo plant . Iran says its nuclear program has a medical purpose , a semi-official newspaper reports . Iran needs to enrich uranium to 20 % for radioisotopes to treat cancer , Kayhan reports .