France's defence minister visited Mali on Tuesday at the beginning of a tour of Africa's Sahel region focused on coordinating action against "the threat of destabilisation" across the vast, rebel-infested hinterland.

Jean-Yves Le Drian flew from Bamako to the northern city of Gao in a plane carrying cargo destined for troops from France's Operation Serval, a miltary mission launched in January to oust Al-Qadea-linked extremists who occupied northern Mali for nine months last year.

The minister met Serval troops and African soldiers from MINUSMA, the United Nations peacekeeping force in Mali, announcing he would return on January 20 to sign a deal reaffirming the military relationship between France and its former colony.

"We will remain by the side of the Malian army, and also MINUSMA, for as long as it takes," Le Drian told reporters.

Analysts agree that Islamists hardened by years of survival under oppressive regimes have been revived across the Sahel, an ungovernable expanse of rock and sand larger than Europe stretching from Senegal in the west to Somalia in the east.

Le Drian will travel on to Niger on Wednesday and Chad the following day, with the crisis in the Central African Republic and French troop numbers across the Sahel expected to dominate his agenda.

"All of us -- the Malian armed forces, MINUSMA, Serval -- we are all preparing to move towards a regional approach. The threat of destabilisation is everywhere," he said.

The visit comes ahead of the January 11 first anniversary of Operation Serval, with armed Islamists driven out of Timbuktu and Mali's other northern cities, but still active in the vast, arid region.

Al-Qaeda in the Islamic Maghreb have carried out several deadly attacks over recent months, with the ongoing threat underlined by the deaths of two Senegalese peacekeepers in a suicide bombing earlier this month.

At the height of the crisis there were 5,000 French soldiers in Mali but the deployment has since been cut in half and France has pledged to reduce its troop presence to 1,000 by the Spring.

"Mali is almost secure, although we must remain vigilant," Le Drian said, adding that there were "areas of weakness" throughout the region, including in Libya, northern Niger and northern Chad.

"I will see with the various heads of state how we can help strengthen security in the entire region," he said.

"We were in a war, (now) we are in a counter-terrorism operation. We must continue along these lines."

Le Drian was due to hold talks in Bamako with President Ibrahim Boubacar Keita before celebrating New Year's Eve with French troops based in the capital.