The European Union moved Wednesday to impose sanctions on three Iranians accused of providing military equipment to support Syria's brutal crackdown on protests, diplomats told AFP.

The EU reached an "agreement in principle" to widen the list of those facing an assets freeze and travel ban by adding seven people, including the three Iranians, and four companies, a European diplomat said.

The Iranians are accused of "providing military equipment and support to help the regime suppress protests in Syria," a diplomat said on condition of anonymity.

The expanded Syrian list, spearheaded by France and Britain, is expected to be formally adopted on Thursday and come into force on Friday during a summit of EU leaders in Brussels.

"We welcome the inclusion of three Iranian names in the extended round of sanctions on the Syrian regime," a British government spokeswoman said in a statement.

"This sends a clear message to the government of Iran that its provision of equipment and technical advice to help the Syrian regime quash protests is unacceptable."

The identities of those targeted by the sanctions will be revealed when the EU publishes its Official Journal on Friday.

Syrian Foreign Minister Walid Muallem denied Wednesday that Syria had received any assistance from ally Iran or Lebanon's militant group Hezbollah in putting down the protests.

He also said Syria regarded EU sanctions as a "war" against Damascus.

Syrian President Bashar al-Assad is among 23 people already on the EU sanctions list.

EU foreign ministers vowed at a meeting on Monday to beef up the sanctions on Syria as they cast doubt on Assad's latest offer of change, with Britain saying he should "reform or step aside."

At the same time, several European nations have joined Washington in pushing for a UN Security Council resolution condemning the Syrian crackdown, but Russia has warned it would veto such a move.

Swedish Foreign Minister Carl Bildt said this week it was vital for the UN Security Council "to express the outrage of the world."

"The silence of the Security Council until now can be seen as an indirect tolerance of what is going on in Syria and that is unacceptable," he said.

German counterpart Guido Westerwelle said Moscow's UN position "goes in the wrong direction".

More than 1,300 civilians have been killed and some 10,000 people arrested, according to Syrian rights groups, in the crackdown that has seen troops dispatched to crush revolt in cities across the Middle Eastern country.