France has introduced a draft resolution to the full United Nations Security Council demanding Iran suspend nuclear activities by the end of August or face the threat of sanctions if it refuses.
US Ambassador John Bolton and other council members hope for a vote next week, although the text can still be changed before then.
Tonight's move comes follows a resolution - introduced last week, and backed by Britain, France and Germany - demanding that Iran stop enriching or reprocessing uranium by next month or face unspecified sanctions.
The initial resolution called on states to prevent trade in ballistic missiles and nuclear technology to Iran. It also would require Iran to submit to more intrusive UN inspections than are required by the 1970 Non-Proliferation Treaty.
The move comes after the council's five veto-wielding members - the US, Russia, China, France, Britain - and Germany admonished Iran for failing to suspend its uranium enrichment programme or respond to incentives offered by global powers.