French President Francois Hollande says airstrikes against Islamic State extremists will accelerate in coming months.

In a speech Thursday to the country's diplomatic corps, Hollande said that this year must be one "of transition in Syria."

France has joined the United States in carrying out airstrikes in Syria and Iraq, but has said peace will come only with the departure of President Bashar Assad. The Nov. 13 attacks in Paris that left 130 dead and hundreds injured were carried out largely by French-speaking Europeans who had trained with Islamic State.

The French president said the allied strategy against the organization "depends upon the liberation of Raqqa in Syria and Mosul in Iraq" — the cities where the extremists have based their command centers.