"Libyans must understand that if they join forces they will be able to get rid of Daesh [ISIL]," Le Drian told Europe-1 radio station. "If they continue [to fight among themselves] it will be a suicide."
Libya has been in a state of turmoil since early 2011 after the Arab Spring protests led to a civil war and the overthrow of long-time leader Muammar Gaddafi. Security vacuum has allowed the Islamic State extremist group to gain ground in Libya.
Le Drian said the ISIL group thrived on internal struggle between tribes and militants loyal to rival Tobruk and Tripoli governments, and warned them that no reconciliation meant "a victory for Daesh."
There are currently two warring governments in the county: the internationally recognized Council of Deputies based in Tobruk and the self-proclaimed General National Congress, based in the capital city of Tripoli.