France is increasing its West African Barkhane counter-insurgency force to support regional forces fighting Boko Haram, Defence Minister Jean-Yves Le Drian said on Wednesday.

"We will slightly increase the numbers on Barkhane to give us the means to support and accompany the tensions that are taking place around Lake Chad," he said, without giving details.

Cameroon, Chad, Niger and Benin have mobilised forces this year to help Nigeria defeat Boko Haram after it seized large amounts of territory and staged cross-border attacks.

France already has about 3,000 troops, excluding special forces, spanning from Mauritania in the West to southern Libya in the East tasked with hunting down al Qaeda-linked groups.