French President Francois Hollande has ordered preparations to begin for air strikes on Islamic State militants in Syria, BBC news reports.

He said France would start reconnaissance flights on Tuesday, September 8, with a view to launching attacks on the group.

Speaking at his bi-annual news conference in Paris, Hollande ruled out sending troops on the ground.

The UN says more than 220,000 people have been killed and more than nine million displaced in the war in Syria.

Hollande said terror attacks had been planned from Syria against several countries, including France.

"My responsibility is to ensure that we are informed as much as possible on the threats to our country," he said, according to the BBC. "So I have asked the defense minister that from tomorrow reconnaissance flights begin over Syria that will enable us to consider air strikes against Islamic State."