France is building up its military intervention in Mali to help quash a rebel offensive but has no current plans to extend operations to northern areas controlled by the Islamists, army chief Edouard Guillaud said on Saturday.

Guillaud told reporters extra military planes had been sent to Africa, after strikes had destroyed half a dozen pick-up trucks belonging to the rebels, and that Rafale fighter jets could strike from bases in France.

"We are in the build-up phase of operations ... As you know we have planes in Africa and have added more," he said, adding that there was no plan to send ground troops towards the north. "The quicker the African mission is on the ground, the less we will need to help the Malian army."