A European deal to freeze Iran's nuclear program, provide the Islamic republic with lucrative trade incentives and avoid sanctions by the U.N. Security Council could be signed by midweek if two critical issues can be quickly resolved, U.S., European and Iranian officials said in interviews Sunday.

Iran has refused to accept a full suspension on all its nuclear-related work and wants a commitment from France, Britain and Germany that a second stage of negotiations will be wrapped up within six months. The European trio wants the later negotiations to be open-ended and expects Iran to maintain a total suspension during that process, diplomats from Britain and France said on the condition of anonymity.

If the deal goes through, European powers have promised Iran a diplomatic and economic package along with a guarantee that it will not be referred to the Security Council, where it could face sanctions.

"If this is approved by all four parties, we will witness an important change in Iran's relations with Europe and much of the international community in [the] not-too-distant future," Iranian negotiator Hossein Mousavian told Iranian television Sunday.

The Bush administration has pushed unsuccessfully for nearly two years to get Iran to the Security Council and has refused to participate in public diplomacy with Tehran. But without proof of a nuclear weapons program, or evidence that Iran is breaking international law, allies have refused to go along with Washington's strategy.

Instead, Britain, France and Germany have devoted the past year to negotiation and compromise with Iran. Talks have been rocky at times but could produce a deal within days.

If negotiations fall apart, Washington expects the Europeans to back its quest for action by the council, Undersecretary of State John R. Bolton wrote in a letter Friday to his counterparts in Paris, London and Berlin, U.S. officials said.

Much of the terms for the Euro-Iranian accord were worked out in two days of meetings that ended Saturday in Paris.

U.S. officials briefed by the three European countries said they believe the deal will go through if Iran accepts a full suspension. Currently, Iran is pushing for an exemption on an early step in the uranium conversion process.

Although the exemption would leave Iran far away from being able to make bomb-grade uranium -- and Iran has said it has no intention of doing so -- it would still get a push in that direction, said David Albright, president of the Washington-based Institute for Science and International Security.

"It would still be a significant step forward and too easy for Iran to conduct the next conversion step in secret," Albright said.

U.S. officials said they will continue to lobby European allies over the next several days to push for the full suspension and an open-ended negotiating period. The officials discussed the negotiations on the condition of anonymity.

"The Iranians will have to give on the timing and the parameters of a suspension," one official said. "Our hope is that the Europeans will agree with that."

Washington also wants more aggressive U.N. inspections, to monitor Iran's compliance with the deal. Legally, Iran isn't obligated to such inspections, but in the past two years, it has granted inspectors access to enrichment facilities and military sites they asked to see.

France, Britain, Germany and Iran signed a similar deal in October 2003; it fell apart within six months, mostly because the terms of the suspension were loosely defined. Iran had also expected European help, which didn't come, in getting its file closed with the International Atomic Energy Agency.

A new deal needs to be worked out soon so the IAEA can verify Iran's suspension before the agency's board meets to discuss Tehran's case on Nov. 25. The IAEA has told parties involved that it will need at least 10 days to complete the work.

Iran, rich in oil and gas, has said its uranium enrichment facility is part of a peaceful nuclear fuel program. But U.S., European and Israeli officials suspect that the scale of Iran's efforts, conducted in secret over 18 years, indicates that it ultimately wants to produce a nuclear weapon.