France raised the prospect on Thursday of providing defensive weapons to Syria's rebels in a conflict now said to have cost more than 39,000 lives, but the United States remained cautious.
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 raise 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."
"The issue of defensive arms will be raised," he added.
France became on Tuesday the first Western country to recognise Syria's newly formed National Coalition as the Syrian people's sole representative.
And President Francois Hollande said the question of arming the rebels would now "have to be necessarily reviewed."
National Coalition chief Ahmed Moaz al-Khatib has called on world powers to arm the rebels with "specialised weapons."
But US President Barack Obama said on Wednesday that while Washington was encouraged by the new coalition it was not yet ready to recognise it, and also cautioned against the growing clamour to supply weapons to the rebels.
"We're not yet prepared to recognise them as some sort of government-in-exile, but we do think that it is a broad-based representative group," Obama said.
"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."
On Saturday, Hollande will meet the coalition's leaders in Paris, Fabius said, including Khatib and George Sabra, president of the Syrian National Council, one of the main components of the newly-formed National Coalition.
Russian Foreign Minister Sergei Lavrov has 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 a plan drafted in Geneva in June.
Damascus had criticised France's recognition of the National Coalition and said a Qatar meeting at which the dissident factions united on Sunday amounted to a war declaration.
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 persons who could not be identified needed to be added to the figure, for a total of 39,112.
Even these figures are short of the real total, because they do not include people of who have disappeared, many of whom are presumed dead, and deaths among the pro-regime "shabiha" militias.
The Observatory relies on a countrywide network of activists and medics in civilian and military hospitals for its numbers.
As the death toll continued to rise, the Observatory said army shelling hit the towns of Daraya and Muwadamiya al-Sham and southern districts of the capital where fighting has been heavy in recent days.
Official media have talked much recently about "terrorist infiltrations" in the capital and its environs, in a reference to rebels, but said the army had managed to foil them.
Militants in both towns said the humanitarian situation there was critical, with electricity cut off and residents rushing for shelters.
In the north of the country, clashes erupted between rebels and soldiers around the airport and at an intelligence headquarters close to the commercial capital Aleppo, while the army shelled the rebel-held town of Aazaz near the Turkish border, the Observatory said.