Iran says talks are "test", U.S. weighs sanctions

TEHRAN (Reuters) - Iran said on Wednesday it viewed talks with six world powers in Geneva as an "opportunity and a test", while the United States weighed sanctions over Tehran's nuclear programme if Thursday's meeting fails.

As Iran's chief nuclear negotiator left for Switzerland expressing goodwill, the head of the U.N. nuclear watchdog said Tehran had broken a transparency law by failing to disclose much earlier a nuclear plant being built for uranium enrichment.