By Adrian Croft and John Irish
BRUSSELS/PARIS (Reuters) - France and Britain will urge European Union governments to lift an embargo on supplying weapons to the Syrian opposition, President Francois Hollande said on Thursday, warning that France could go it alone if no EU agreement is reached.
The French president justified his call to increase help to the Syrian opposition after a two-year uprising against President Bashar al-Assad by saying that weapons were being delivered to Assad's government, particularly by Russia.
"We want the Europeans to lift the arms embargo - not to go towards a total war, we think a political transition must be the solution for Syria - (but) we must accept our responsibilities," he said as he arrived for an EU summit in Brussels.
"(We) cannot allow a people to be massacred as it is being today," said Hollande, adding that Britain saw eye-to-eye with France on the issue.
He said France and Britain aimed to persuade their EU partners during discussions on the second day of the summit to lift the embargo for the opposition before the end of May.
If agreement at EU level is not possible, he indicated that France could go it alone in abandoning the embargo.
"If by chance one or two countries were to block the move ... I can't speak for others, but France itself would take its responsibilities," he told a news conference.
The arms ban is part of a package of EU sanctions on Syria that rolls over every three months. An extension agreed last month expires on June 1. Without unanimous agreement to renew or amend it, the embargo lapses, along with the sanctions.
France and Britain have stepped up calls to lift the restrictions to permit supplies to the Syrian opposition in a conflict that has cost 70,000 lives.
But other EU governments, including Germany, have resisted the move, fearing it will fuel violence in the region, especially if arms get into the hands of militant Islamists.
Chancellor Angela Merkel said Germany was ready to discuss the issue but warned of the risk that lifting the arms embargo for the rebels could lead to escalation of the conflict.
"We as Germany will be taking a very measured approach. On the one hand it's dramatic to see that in Syria bloodbaths occur again and again and how many victims there are already. But one also has to make sure that the opposing side doesn't then get provided with weapons by countries that take a different stance on Assad than Germany," she told a news conference.
"So in that sense it's a very complicated evaluation for us but Germany is ready to discuss this on the level of foreign ministers," she said.
Western diplomats say Iran has significantly increased military support to Assad in recent months, solidifying its position alongside Russia as the government's lifeline.
A spokeswoman for British Prime Minister David Cameron said he was determined to bolster the mainstream Syrian opposition.
"What we want to do is inject some political momentum from the highest level of government across the EU into the discussions," she said, adding the embargo was "backfiring".
"It doesn't stop those aiding Assad, it does stop EU countries and others helping those against whom Assad is waging a brutal and terrorising war," she said.
A senior French official who spoke on condition of anonymity said anti-aircraft missiles were among weapons that might be supplied to already identified groups of rebel fighters.
After weeks of wrangling, Britain last month won EU agreement to relax the embargo to allow non-lethal but quasi-military aid to the opposition, such as armoured vehicles.
Echoing comments by Russia, which has protected Assad from any U.N. measures, Syria's state news agency SANA said arming rebels would be a "flagrant violation of international law".
(Additional reporting by Jonathon Burch in Ankara, Erika Solomon in Beirut, Julien Ponthus, Justyna Pawlak, Annika Breidthardt and Peter Griffiths in Brussels, and Michelle Martin in Berlin; Editing by Alistair Lyon and Michael Roddy)