* Le Drian tells troops France proud but mission not over
* DNA tests being carried out to identify Islamist leaders
* Mali creates Dialogue and Reconciliation Commission (Adds Le Drian quotes, Liberation report)
By Emmanuel Braun
GAO, Mali, March 7 (Reuters) - France will only hand over to African troops in Mali when security is restored, French Defence Minister Jean-Yves Le Drian told his forces during a surprise visit to the rugged north of the country where they are battling Islamist rebels.
Reviewing the ranks of French soldiers in the dusty Adrar des Ifoghas mountains, Le Drian paid homage to the courage of troops engaged in fierce fire-fights with al Qaeda militants in the desolate desert region near the Algerian border.
An eight-week, French-led offensive has broken the control of al Qaeda-linked Islamists over the northern two-thirds of the impoverished landlocked nation, though pockets of resistance remain in the desert and mountains.
"Our mission is to liberate Mali, strengthen the country, and to assure sovereignty," Le Drian said in Gao, the main town in northern Mali, shortly after he visited troops in the mountains. "The security of Mali, and the security of our country, go together," he said.
France launched a ground and air operation on Jan. 11, saying the Islamist rebels' hold of Mali's north posed a risk to the security of West Africa and Europe.
Having halted a push southward by Islamist rebels, French forces have driven militants out of major towns and, alongside hundreds of Chadian soldiers, are now seeking to clear rebels from cave redoubts in the Adrar des Ifoghas.
"We are in the last phase, the most decisive phase," Le Drian said. "This phase entails some very violent combat. When the liberation of the whole country is complete, then we will hand over responsibility to African forces."
President Francois Hollande said on Wednesday that France would start to draw down its forces in Mali from April, a month later than previously forecast.
HOPES FOR U.N. PEACEKEEPING MISSION
France is keen to hand responsibility for operations in Mali to an 8,000-strong African-led force AFISMA, some three-quarters of which has already deployed to the landlocked country.
Paris is pushing for the Mali mission to be given a U.N. peacekeeping mandate once offensive military operations have finished. The Security Council is expected to discuss this in the coming weeks.
A Malian soldier who was involved in fighting with Islamists who killed a French soldier on Wednesday said the resistance was still fierce just 90 km from Gao.
"I cannot say how many (rebels) there were but gunfire was coming from every direction," the soldier told Reuters, asking not to be named as he was not authorised to speak to the press.
"We killed them all, but it is not over. They have reinforcements ... They are in the forests and they are not leaving," he added.
Chad has claimed to have killed al Qaeda's two top leaders in the region, Abdelhamid Abou Zeid and Mokhtar Belmokhtar.
Hollande said on Wednesday that "terrorist leaders" had been killed in the operation, but did not provide further details.
French Foreign Minister Laurent Fabius said DNA testing was being carried out on the bodies of hundreds of dead Islamist fighters.
"To identify the two or three leaders who have been cited, we have to carry out precise tests with DNA and that is what the army services are doing," he told RTL radio. "We should know fairly quickly."
France's Liberation newspaper reported on Thursday that a French citizen fighting in the Islamist ranks had been taken prisoner by the French.
Even once fighting is over, a durable peace in Mali will also require unifying the country's south, home to the capital Bamako, with the vast desert north, where Tuareg separatists launched a rebellion last year that was hijacked by Islamist fighters.
Many in southern Mali now feel deep resentment toward the northern Tuaregs and light-skilled Arabs, associated with the Islamist fighters, complicating prospects for peace.
President Dioncounda Traore's government, which aims to hold national elections in July, announced the creation of a Dialogue and Reconciliation Commission on Wednesday, charged with identifying human rights abuses during the conflict and deciding which armed groups were eligible to participate in talks. (Additional reporting by Tiemoko Diallo in Bamako and Vicky Buffery in Paris; Writing by Daniel Flynn and David Lewis; Editing by Jon Hemming)