French Defence Minister Jean-Yves Le Drian on Monday urged African nations to combine efforts to tackle the jihadist threat, from southern Libya to Nigeria.

"Cooperation must become the rule and no longer the exception," Le Drian said at the opening of the first International Forum on Peace and Security in Africa, in Senegal's capital Dakar.

"The threat feeds off the absence of borders and their porous nature. Southern Libya is today the most dramatic example," he said, referring to the regrouping of Islamic extremist movements since French military intervention helped drive them from towns in northern Mali in 2013.

"The situation in the south of Libya today is a source of destabilisation for the whole of the Sahel" belt of nations on the southern edge of the Sahara.

As for the brutal Nigerian sect Boko Haram, "the issue is no longer whether it's a national or regional problem. (Cross border) attacks in the north of Cameroon give us an answer. We need a joint and coordinated regional response," Le Drian said.

The sluggish nature of current cooperation efforts is illustrated by the time it is taking Nigeria, Cameroon, Niger and Chad to deploy 2,800 soldiers to the region where their borders meet, confronted with Boko Haram.

Le Drian commended the readiness of African states to deploy peacekeeping troops across the continent. But the African Union's commissioner for peace and security, Smail Chergui, said that African nations should "take up their part in financing" such efforts, alongside European countries.

The Dakar forum is intended to become an annual meeting.