Political directors from the main powers involved in trying to rein in Iran's nuclear programmes are due to meet in Moscow on Tuesday to discuss what action to take after Tehran announced this week it had become a nuclear power by enriching uranium.

The senior officials from France, Germany, Britain, the United States, Russia and China will look at "real actions" the United Nations can take to get Iran to change its behaviour, said State Department spokesman Sean McCormack.

The options under a Chapter 7 resolution under the UN charter could include a freeze on assets and travel restrictions on some members of the Iranian government, said McCormack.

"These are all levers at the disposal of the international community," McCormack told reporters.

While pushing for sanctions, US officials said they would not look at imposing restrictions on the oil and gas sectors, pointing out the intention was not to create further hardship for the Iranian people.

In an interview with Voice of America's Persian language television programme, senior State Department official Nicholas Burns said Tehran would face sanctions and that Iran had left itself "no exit points" on the Iran issue.