The US is considering offering economic incentives to Iran in exchange for abandoning any plans to develop a nuclear weapon, US officials say.
Suspicions remain over Iran's nuclear ambitions despite extensive inspections
White House spokesman Scott McClellan said President George W Bush was looking at ideas discussed with European leaders last week.
Correspondents say US backing for the European plan would mark a significant shift in Washington's policy.
The EU has tried to negotiate with Iran but the US has urged a tougher stance.
The US accuses Iran of using its civilian nuclear power programme as a cover to develop nuclear weapons.
Tehran insists its nuclear programme is peaceful.
Late last year, Tehran agreed with the European Union to freeze its uranium enrichment programme - a process which can be used for nuclear power plants or nuclear weapons.
France, the UK and Germany are now trying to persuade Iran to make the freeze permanent in exchange for trade and technology benefits.
"The president is considering ideas that were discussed last week in Europe for moving forward on our efforts to get Iran to end its pursuit of nuclear weapons and abandon its nuclear weapons ambitions," Mr McClellan said.
The spokesman did not say when Mr Bush might make a decision.
Reports say proposed incentives may possibly include Iran's eventual membership in the World Trade Organisation.
Earlier on Monday the head of the UN nuclear watchdog called on Iran to do more to co-operate with the agency's inspections.
IAEA head Mohamed ElBaradei said that inspections were "moving forward", but the agency was still not sure it had seen all areas of Iran's activities.