Iran has significantly stepped up military support to Syrian President Bashar al-Assad in recent months, solidifying its position alongside Russia as the government's lifeline in an increasingly sectarian civil war, Western diplomats said.
Iranian weapons continue to pour into Syria from Iraq but also increasingly along other routes, including via Turkey and Lebanon, in violation of a UN arms embargo on Iran, Western officials told Reuters on condition of anonymity. Iraqi and Turkish officials denied the allegations.
Meanwhile, on Thursday, French President François Hollande said his country and Britain are pushing the European Union to quickly lift its arms embargo on Syria so that they can send weapons to rebel fighters. He insisted that the rebels are fighting on an uneven battlefield because Russia and others are arming Syrian President Mr. al-Assad's regime.
"France must first convince its European partners. But we cannot let a people be massacred like this," Mr. Hollande told reporters in Brussels where he is attending an EU summit. "So already the British and French are in favour of lifting the embargo."
The British government said that it is not ruling out any options to help the opposition.
Iran's acceleration of support for Mr. al-Assad suggests the Syrian war is entering a new phase in which Iran may be trying to end the battlefield stalemate by redoubling its commitment to Mr. al-Assad and offering Syria's increasingly isolated government a crucial lifeline, the envoys said.
It also highlights the growing sectarian nature of the conflict, diplomats say, with Iranian arms flowing to the Shiite militant group Hezbollah. That group is increasingly active in Syria in support of Mr. al-Assad's forces, envoys say.
Alireza Miryousefi, spokesman for Iran's UN mission, responded to a request for a comment by saying, "We believe Syria does not need any military help from Iran."
Syria's UN ambassador, Bashar Ja'afari, had no specific comments on the matter.
The Syrian conflict started out two years ago as a pro-democracy movement. Some 70,000 people have been killed and more than one million refugees have fled the violence.
A Western intelligence report seen by Reuters in September said Iran was using civilian aircraft to fly military personnel and large quantities of weapons across Iraqi airspace to aid Mr. al-Assad.
Iraq denied that report but later made a point of inspecting an Iran-bound flight that it said had no arms on board.
Much of the weaponry going to Syria now, diplomats say, continues to be shipped to Iran through Iraqi airspace and overland through Iraq, despite Baghdad's repeated promises to put a stop to Iranian arms supplies to Mr. al-Assad in violation of a UN arms embargo on Tehran over its nuclear program.
"The Iranians really are supporting massively the regime," a senior Western diplomat said this week.
"They have been increasing their support for the last three, four months through Iraq's airspace and now trucks. And the Iraqis really are looking the other way."
Israel's chief of military intelligence Major-General Aviv Kochavi also said on Thursday that Mr. al-Assad was "making preparations to use chemical weapons although he has not yet given orders to do so, and increasing operations with Hezbollah and Iran."
With a report from Associated Press