The United States and the European Union are calling on the UN nuclear watchdog to report Iran to the Security Council over its nuclear activities.
Iran says it has a right to produce nuclear energy
France, Britain and Germany circulated a rough draft of a resolution seeking the move as the International Atomic Energy Agency met to discuss the issue.
US envoy Greg Schulte says Iran is pursuing a course of confrontation by continuing its conversion of uranium.
But key countries on the IAEA board oppose Security Council involvement.
The government in Tehran has denied US claims that it is secretly trying to develop nuclear weapons.
It is not clear whether the IAEA's board of governors will agree to refer the matter to the UN's highest body, says the BBC's Bethany Bell at the IAEA headquarters in Vienna.
Earlier the head of the IAEA, Mohammed ElBaradei, said the international community was going through a period of confrontation over Iran's nuclear programme, and called on all parties to work together to return to the negotiating table.
Ambassador Schulte would not be drawn on any details as to the time of the proposed referral to the Security Council, which has the power to impose sanctions.
"Our goal... remains to achieve a diplomatic solution," he told the BBC.
"But this will require Iran to change its course and to co-operate fully with the IAEA to cease its conversion activities and to go back to the negotiating table."
The three European nations have been working to convince the 35-nation board to report Iran to the Security Council following Tehran's decision in August to resume sensitive uranium conversion work.
They distributed the draft resolution to the board on Monday, diplomats said. It could be voted on this week.
Russia, China, Brazil and other developing countries have expressed a reluctance to refer Iran to the Security Council amid fears the dispute could escalate still further.
The board's 14 members of the Non-Aligned Movement met on Monday to forge a common position, diplomats quoted by Reuters said.
All but two of these are said to want the issue to be resolved within the IAEA, the diplomats said.
Russia has reportedly asked the EU to delay referral, with Foreign Minister Sergei Lavrov making the appeal on the sidelines of the UN General Assembly meeting in New York.
Iran insists it has an "inalienable right" to produce nuclear energy.
In a speech to the UN General Assembly, President Mahmoud Ahmadinejad said Iran's programme was entirely legal and attacked what he called a "nuclear apartheid" that permits some countries to enrich fuel, but not others.
The US and EU took the speech as a rejection of negotiations and incentives they offered to Iran to give up its nuclear programme.
Ahead of the IAEA meeting, the agency's director, Mohamed ElBaradei, called on Iran to finally allow access to sensitive sites and key people.
He said the "ball is very much in Iran's court on this issue".