"The Security Council has the international legal and political authority that will bring this issue to a successful and peaceful resolution," US ambassador Jackie Sanders said in the text of a speech delivered at a meeting of the UN International Atomic Energy Agency's (IAEA) board of governors.
She said the Security Council also "has the authority to require and enforce a suspension of Iran's [uranium] enrichment-related and [plutonium] reprocessing activities", something Tehran has done voluntarily.
Washington accuses Iran of developing nuclear weapons under cover of a civilian atomic energy programme. Tehran denies this, saying its nuclear ambitions are limited to the peaceful generation of electricity.
"The [IAEA] board cannot ignore forever its statutory obligation to report this matter to the UN Security Council," Sanders said, referring to what she described as Iran's "non-compliance" with the nuclear Non-Proliferation Treaty (NPT).
US President George Bush, at the request of key European allies, is considering whether to join forces with France, Britain and Germany, which have offered Tehran economic and political incentives to scrap its enrichment programme. Iran refuses to permanently abandon the programme, saying the production of enriched uranium fuel - a process that can be used to make fuel for power plants or weapons - is a sovereign right it will never give up.