France raised the prospect on Thursday of providing Syria's rebels with defensive weapons in a conflict now said to have cost more than 39,000 lives, but Damascus ally Russia said this would violate international law.
The diplomatic manoeuvring comes as Syria's army pressed an operation in areas around Damascus to rout rebels who have stubbornly clung to gains made in July, and as fighting raged on northern battlefields.
In Paris, Foreign Minister Laurent Fabius raised the issue of excluding defensive weapons from the current European Union arms embargo on Syria to help rebels fighting President Bashar al-Assad's regime.
"For the moment, there is an embargo, so there are no arms being delivered from the European side. The issue... will no doubt be raised for defensive arms," he told RTL radio.
"The issue will be raised because the (opposition) coalition has asked us to do so," he said, adding that "this is something that we can only do in coordination with the Europeans."
"France's position for the moment is to say that we must not militarise the conflict, but it is evidently unacceptable that there are liberated zones and that they be bombarded by Bashar's planes,"
On Tuesday, National Coalition chief Ahmed Moaz al-Khatib called on world powers to arm the rebels with "specialised weapons."
The same day, France became the first Western country to recognise the newly formed coalition as the Syrian people's sole representative.
In Moscow, Russian foreign ministry spokesman Alexander Lukashevich said "promises are being made from a number of capitals of massive supplies of modern weapons.
"Outside help to the opposition waging an armed battle against a legitimate government is a gross violation of fundamental norms of international law."
Lukashevich added that the latest developments, including what he said was rebel refusal to talk with Assad, were "in direct contravention" of the so-called Geneva peace plan championed by former UN negotiator Kofi Annan.
On Wednesday, Russian Foreign Minister Sergei Lavrov said the priority must be to end the bloodshed rather than form an opposition bloc that refuses to negotiate.
"It is essential that an end to bloodshed in Syria is reached," Lavrov said in Riyadh on Wednesday after meeting Gulf Arab leaders, adding that key to that was the Geneva plan.
For his part, US President Barack Obama was cautious about the arms question.
"One of the things we have to be on guard about... is that we're not indirectly putting arms in the hands of folks who would do Americans harm," he said on Wednesday.
However, he said Washington was encouraged by the new coalition but was not yet ready to recognise it.
Meanwhile, the death toll in 20 months of conflict has topped 39,000, a watchdog said on Thursday.
The Syrian Observatory for Human Rights said 27,410 civilians, 9,800 soldiers and 1,359 military deserters had been killed since the uprising began on March 15, 2011.
Observatory chief Rami Abdel Rahman said another 543 people who could not be identified needed to be added to the figure, for a total of 39,112.
The Observatory relies on a countrywide network of activists and medics in civilian and military hospitals for its toll figures.
As the death toll continued to rise, the Observatory said army shelling hit the towns of Daraya and Mudamiyeh al-Sham and southern districts of the capital where fighting has been heavy in recent days.
Militants in both towns said the humanitarian situation there was critical, with electricity cut off and residents rushing for shelter.
On Wednesday, a day that saw 126 people killed nationwide, shelling and clashes in the the Damascus area left 21 people dead, the Observatory said,
It gave an initial toll of 39 people killed nationwide on Thursday.
In the north, clashes erupted between rebels and soldiers around the airport and at an intelligence headquarters close to the commercial capital Aleppo, and the army shelled the rebel-held town of Aazaz near the Turkish border, the Observatory said.
Elsewhere, the army made a major incursion into the Homs city district of Al-Waar and the Homs provincial town of Qusayr, near the Lebanese border, with casualties reported in both places, the watchdog said.