* Loyalist Tuareg sees Islamists holding out in mountains
* France "must continue mission until Mali army in control"
* Mali needs process of internal reconciliation, Gamou says
By David Lewis
GAO, Mali, Feb 15 (Reuters) - The top Tuareg officer in Mali's army urged France on Friday to keep its forces in Mali for as long as it takes to drive out Islamist rebels for good.
Colonel El Hadj Ag Gamou, who remained loyal to Mali's government last year when fellow Tuaregs rebelled, said an early withdrawal by French troops would allow the Islamist forces, linked to al Qaeda, to regain ground lost in a five-week-old French-led offensive.
"They (the French) have started something that is not close to being finished," he said.
After pushing Islamist insurgents from north Mali's major towns with relentless air strikes and rapid advances by special forces and armoured columns, and backing from former Tuareg rebels, France's leaders have said they intend to start withdrawing the 4,000 French troops next month.
But Gamou, who is a commander in the Malian army, said he expected the jihadist insurgent groups to fight a guerrilla war from the remote and rugged Adrar des Ifoghas mountains into which they had retreated, near Algeria's border.
"This is where they organised themselves ... and that is where they can hide and resupply. They are protected by nature - there is water," Gamou told Reuters in an interview, sitting in desert fatigues and beige turban in a sandy compound flanked by men from his unit, almost all Tuareg desert fighters like him.
The Tuaregs are desert dwellers who live mostly in Mali's Saharan north as well as in neighbouring Niger and Algeria.
"NEUTRALISE THE THREAT"
Gamou said France should not withdraw from its former colony until the Malian army could maintain government control over the sprawling state, Africa's third largest gold producer after South Africa and Ghana.
"The French have to continue their mission until the threat is neutralised ... and Mali's army is able to control the whole country," the Tuareg officer said softly as the desert wind whipped through the shade of the thatched hut.
Gamou only came back to Mali last month with his men after months of exile in neighbouring Niger, returning to the Saharan town of Gao, recaptured from the insurgents three weeks ago.
He said the rebels' links with Libya, Algeria and Tunisia and their history of ties with smuggling networks across the vast Sahara gave them the ability to bring in supplies across the mountain passes and uncontrolled, porous borders.
French soldiers and their military allies from Mali and Niger have already faced suicide bombings and raids from holdout Islamist fighters in and around Gao, which remains tense.
Some see the French becoming bogged down in a debilitating counter-insurgency war in a tough and inhospitable Saharan battleground, but French military spokesmen and leaders have repeatedly ruled this out.
Gamou, whose own loyalist unit is based at a half-built petrol station in Gao, estimated the combined number of Islamist fighters remaining in northern Mali at 2,500.
This is roughly the same as the figure given by West Africa's ECOWAS bloc before the French campaign inflicted what French leaders say were "hundreds" of losses on the Islamists.
WEST AFRICAN FORCE
ECOWAS troops form the bulk of a U.N.-backed African military force, expected to number 8,000, that is moving up behind the French and Malians to provide security at recaptured towns, roads and bridges. But its deployment has been slowed by delays, and lack of airlift capacity and equipment.
Beyond counter-terrorism operations, Gamou said Mali needed a long process of internal reconciliation, during which he said distinctions should be made between those in the northern Tuareg and Arab communities who took up arms against the central government in Bamako and those who did not.
"People don't understand what is going on in the north," he said. "There is the population and there are the armed groups. The population is not represented by the armed groups."
Interim President Dioncounda Traore, installed last year after a military coup - which triggered the Tuareg separatist revolt in the north that was hijacked by the jihadists - has said elections will be held in July.
Under pressure from France and the West, Traore has said his government is ready to talk to the Tuareg rebels, provided that they drop any claims of independence for their territory.
The Tuareg rebel group MNLA has said it is willing to accept Mali's internationally recognised borders and fight against al Qaeda and its allies.
Last year, after resisting the anti-government rebels for weeks, Gamou pretended to join them to save his men from annihilation, but then led his unit into exile across the border in Niger and remained loyal to the government in Bamako. (Editing by Pascal Fletcher and Kevin Liffey)