French Defense Minister Jean-Yves Le Drian estimated his the country's military operation in Mali cost 50 million euros (67.82 million U.S. dollars) so far.

Speaking to France Inter radio, the minister said three weeks of military commitment in the French former colony cost the government so much "mostly related to logistical issues."

"Every year, there is a budget for external operations at 630 million euros that allows French forces to commit in such circumstances," Le Drian added.

After retaking major Malian towns of Gao and Timbuktu, French forces on Wednesday took control of the airport in Kidal, the last town held by Islamists insurgents.

France deployed some 4,500 troops in a three-week ground and air offensive to help Malain authorities to quash Islamists rebels that seized the country's northern region 10 months ago.