Speaking to the Chicago Council on Foreign Relations on Wednesday, Condoleezza Rice said the international community agreed Iran could not have a nuclear weapon and was mobilised to respond.
On Tuesday, George Bush, the US president, had refused to rule out nuclear strikes against Iran if diplomacy failed to curb the Islamic Republic's nuclear ambitions.
"In order to turn the Iranians back from what has been behavior that is contrary to all the wishes of the international community, we are prepared to use measures at our disposal - political, economic, others, to dissuade Iran," Rice said in reply to a question on Iran.
When asked what the threshold would be for military action against Iran, Rice reiterated that political and economic pressure should run its course. However, she stressed the president's view that all options remained on the table.
Officials from Britain, France, Germany, the United States, Russia and China have been meeting in Moscow, so far without agreement, trying to find a united approach on Iran, which announced last week it had begun to enrich uranium.
"The issue here is to mobilize the international community, to unify the international community around the view that Iran cannot have a nuclear weapon. That is agreed."
Condoleezza Rice, the US secretary of state
The United States and its European allies say Tehran could divert highly enriched uranium to make bombs while Iran says the programme is for civilian use to meet growing energy needs.
"The issue here is to mobilize the international community, to unify the international community around the view that Iran cannot have a nuclear weapon. That is agreed," Rice said.
She said the United States had a number of "diplomatic tools at our disposal to persuade the Iranians that they really need to come back to negotiations." She did not elaborate.
Meanwhile, oil prices hit a new high above $73, partly driven by fears that the dispute could disrupt shipments from the world's fourth-largest oil exporter.