France will ask for an urgent U.N. Security Council ministerial meeting on Syria to try to end the diplomatic deadlock and prevent further bloodshed, Foreign Minister Laurent Fabius said on Monday.
President Bashar al-Assad's forces attacked rebel fighters in the city of Aleppo at the weekend, drawing condemnation from Western powers who say the authorities in Syria have lost all legitimacy.
Branding Assad an "executioner", Fabius said the country was headed for a massacre, and urged the United Nations to do everything it can to stop the crisis.
"We're going to ask for a meeting of the Security Council, probably at ministerial level, before the end of this week," he told RTL radio.
Western powers have thus far been unsuccessful in ending an impasse at the U.N. over the Syrian crisis, with Russia and China trying blocking efforts to put more pressure on Assad.
France is due to take over the presidency of the United Naations Security Council on Wednesday, and President Francois Hollande has said he will try to convince Russia and China to support further sanctions.