After talks in London that also included officials from China, Russia and the United States, the so-called “EU-3” said it wanted the 35-nation board of governors of the International Atomic Energy Agency (IAEA) to meet on February 2-3.
"The EU-3 informed the other participants of their intention to call for an extraordinary IAEA board of governors meeting on the 2nd and 3rd of February," a British Foreign Office spokesman said.
Britain, France and Germany have spearheaded the EU's negotiations with Iran, trying to woo the Islamic republic with pledges of more aid and trade in return for greater candour on its nuclear program.
The London gathering followed Iran's announcement last week that it was to resume research into uranium enrichment, sparking worldwide concern.
Last Thursday, the EU-3, furious at Iran breaking the seals on nuclear facilities to resume fuel work, declared the talks were at a "dead end" and said they would seek an IAEA meeting to debate referral.
’Civilian’ program
Iran insists its nuclear program is purely for civilian energy purposes, but highly enriched uranium can also be used as the raw material for nuclear weapons -- something the West fears Iran is secretly trying to develop.
The IAEA could decide to refer Iran to the Security Council for contravening nuclear non-proliferation agreements and IAEA resolutions, in a possible prelude to sanctions.
However, a lesser measure such as a formal order for Iran to halt nuclear research appears more likely, with British Foreign Secretary Jack Straw saying on Monday that there was no need to "rush" towards sanctions.
Russia and China, both of which have close trade and energy ties with Iran, are also seen as less keen on sanctions than the US and the EU.
Over the weekend, Iran declared it was "not scared" at the prospect of UN referral.
The British Foreign Office spokesman said all sides in Monday's talks had expressed "serious concern" about Iran's move but talked only of "a thorough exchange of views on the role of the UN Security Council" in enforcing the IAEA's views.
"The participants remain committed to a diplomatic solution," the spokesman added.
A European diplomatic source, speaking anonymously, had earlier described referral to the Security Council as a certainty.
"The Russians are agreed now. They have changed their position," said the source. "The Chinese are still a little hesitant, but effectively a Security Council referral is now a done deal."
The diplomatic source, however, stressed that sanctions, while possible, were by no means a certainty.
"There are plenty of examples where a matter is referred to the Security Council and the Security Council takes action and that action is followed without sanction," the source said.
In Moscow, President Vladimir Putin cautioned against taking "abrupt" steps over Iran and stressed that a long-mooted compromise plan to enrich uranium for Iran on Russian territory was still possible.
"The Iranian foreign ministry, notably, has said that it does not rule out accepting our proposal," Mr Putin said after talks with German Chancellor Angela Merkel.
Meanwhile, Iran's ambassador in Moscow welcomed Mr Putin’s offer to enrich uranium for Iran in Russia.
"This is a good initiative to find a way out of this situation. We think that Iran and Russia should find a way out together," Russia’s ITAR-TASS news agency quoted Gholamreza Ansari as saying in comments broadcast on Russia's state-owned Channel One television.
US Secretary of State Condoleezza Rice, en route to Liberia, said on Monday she wanted to see the board of the IAEA convene "as soon as possible".
"The problem with waiting for the regular meeting in March or waiting for a long time is that I think the Iranians will try to take advantage of it,” she said.