The United States has reached an agreement with France, Britain and Germany on a draft UN nuclear resolution condemning Iran's 18-year cover-up of the full extent of its nuclear programme.
"The resolution has been tabled," a Western diplomat told journalists, adding that it had been formally introduced to the UN International Atomic Energy Agency (IAEA) for discussion at Wednesday's IAEA Board of Governors meeting.
He said the resolution would likely be acceptable to the entire 35-member board. The US has accused Iran of pursuing a nuclear weapons programme, a charge Tehran denies.
The latest version called for the IAEA's governing board to "meet immediately to consider all options at its disposal" if any further violations of Tehran's international non-proliferation obligations are uncovered.
A senior US State Department official said that US negotiators pushed the Europeans to strengthen the wording of what the US calls a "trigger mechanism" to warn clearly Iran that if Tehran is guilty of any more violations it may be reported to the UN Security Council for possible sanctions.