France's Prime Minister Manuel Valls said on Tuesday a deal with Syrian President Bashar al-Assad to reach a political transition was impossible, but said Paris would back regional ground troops if they were to intervene against Islamic State militants.
President Francois Hollande on Monday said that French air strikes against the group in Syria would be necessary, a change in position after previously warning any such action could reinforce Assad.
"We will do nothing to strengthen the regime," Valls said in a speech to parliament to explain France's decision to launch reconnaissance flights and future action over Syria.
"The urgency, on the contrary, is to reach an agreement that definitively turns the pages of Assad's crimes ... with a man responsible for so many dead and crimes against humanity, no compromise or deal is possible."
France until now had only taken part in air strikes against Islamic State in Iraq, while also providing limited logistical support to rebels it deems moderate in Syria.
But Valls said the change in strategy was needed given the expansion of Islamic State over the last year and the threat its militants could have on French interests at home and abroad.
"Daesh is the new totalitarianism. It uses Islam to impose itself and does not back down against anything," he said, using the Arabic acronym for Islamic State.
Despite calls among key French opposition party leaders to send troops to fight the group and talk to Assad, Valls ruled both of those options out.
"Sending tens of thousands of soldiers ... would be the trap that the jihadists have set for us," Valls said. "But if a regional coalition were created to free Syria from the tyranny of Daesh, then these countries would have the support of France," he said without elaborating.
He reiterated that the only solution to the Syria crisis was through a political transition that would see Assad leave power.
"We need to speak to everybody ... in particular with Russia whose positions are still far from ours. We all have a responsibility - all military aid to Assad's regime will only feed the spiral of violence."
