"Progress on the political front will be difficult, I have to confess," the French ambassador to the UN, Gerard Araud said on Saturday.
But things can be done "on the humanitarian front, because above and beyond the deadlock on the Security Council or the resignation of international Syria envoy Kofi Annan, there is the suffering of the Syrians."
The international community has failed to bring a halt to the conflict that activists say has killed at least 21,000 people since President Bashar al-Assad's regime launched a brutal crackdown on dissent in March last year.
France took over the rotating presidency of the Security Council for a month from 1 August.
"We will try to work to bring China and Russia around at least on humanitarian questions," he said, adding that French Foreign Minister Laurent Fabius planned to chair a ministerial meeting of the Security Council at the end of the month.
"There are three million Syrians who currently lack food and medicine. There is no access to humanitarian aid, except for the Syrian Red Crescent, which is working wonders but is completely overwhelmed."
Araud said he hoped Russia and China would "listen to the international community," in the wake of Annan's dramatic resignation on Thursday.
Russia and China, which have vetoed three Security Council resolutions on Syria, were among high-profile opponents of a UN General Assembly resolution adopted on Friday condemning Assad's use of "heavy weapons" and the regime's "massive and systematic violations of human rights."
"The Russians tell us that as they see it, it is Assad or the Islamists, and while they don't particularly like Assad, they don't want the Islamists," Araud said.
"We are telling them that with the line they are taking, it will be Assad and then the Islamists. Because Assad will fall and the longer we wait, the more radical the resistance will be. Already we are seeing Al-Qaeda in Syria and at the end of the day, we will have the outcome that the Russians fear.
"We must convince the Russians and Chinese that they are going down the wrong road and that they will drag us into a final disaster, civil war, chaos, and in the end perhaps the victory of the radicals," he said.