Tehran's ambassador to the United Nations in Vienna said today a draft nuclear resolution on Iran was the result of US "bullying".
Ambassador Mr Pirooz Hosseini said European nations should have done more to stand up to Washington.
The United States said a resolution circulating among International Atomic Energy Agency's (IAEA) board members would tell Iran it would be punished if it defied the watchdog but stopped short of reporting Tehran to the UN Security Council for possible sanctions.
"The three European countries tried their best. We expected more from our European colleagues," Mr Hosseini told reporters, describing the US approach to discussions in the governing board as an "act of bullying".
"We think that a lot of bullying is involved here by the Americans to subdue a healthy process here," Mr Hosseini said. "We think that the Americans do not want to accept the fact that Iran is not for nuclear weapons programmes."
The preliminary draft, still being revised by co-authors Australia and Canada, was the result of a compromise between the United States and France, Britain and Germany.
Last month, the European Union's "Big Three" told Iran they would try to block any resolution on Tehran's nuclear programme in exchange for Iran's promise to suspend everything related to its uranium enrichment programme. But they later agreed to back a resolution that did not report Iran to the Council.
Washington accuses Tehran of using a civilian nuclear programme as a cover for developing atomic weapons. Iran strongly denies it the charge.