French-led troops have entered Kidal in the north of Mali, the last major town they have yet to secure in their drive against Islamist militants.
French forces now control Kidal airport after a number of aircraft, including helicopters, landed there overnight.
Islamist militants were reported to have already left the town and it was unclear who was in charge.
French and Malian forces have been sweeping north, earlier taking Gao and Timbuktu with almost no resistance.
France – the former colonial power in Mali – launched a military operation this month after Islamist militants appeared to be threatening the south.
French army spokesman Colonel Thierry Burkhard confirmed that: “French elements were deployed overnight in Kidal.”
One regional security source told Agence France-Presse that French aircraft had landed at Kidal and that “protection helicopters are in the sky”.
Kidal, 1,500 km (930 miles) north-east of the capital Bamako, was until recently under the control of the Ansar Dine Islamist group.
However, the Islamic Movement of Azawad (IMA), which recently split from Ansar Dine, said it was now in charge in Kidal, although the Tuareg group – the National Movement for the Liberation of Azawad – also claims control.
An MNLA spokesman said its fighters had entered the city on Saturday and there were no Islamist militants there.
Some reports say Ansar Dine leader Iyad Ag Ghaly and Abou Zeid, of al-Qaeda in the Islamic Maghreb, have moved to the mountainous region north of Kidal.
French-led troops have entered Kidal in the north of Mali, the last major town they have yet to secure in their drive against Islamist militants
A spokesman for the IMA confirmed the French arrival in the town and said that its leader was now in talks with them.
The IMA recently said it rejected “extremism and terrorism” and wanted a peaceful solution.
The MNLA has also said it is prepared to work with the French “to eradicate terrorist groups” in the north but that it would not allow the return of the Malian army, which it accused of “crimes against the civilian population”.
Taking Kidal will mark the end of the first phase of the French military intervention, but that there will remain the difficult task of chasing the fighters down across the vast desert.
Islamist extremists took advantage of a military coup in March last year to control a number of cities in the north and impose Sharia law.
The French arrival at Kidal came only 24 hours after securing Timbuktu with Malian forces.
The troops had to secure the streets after hundreds of people looted shops they said had belonged to militant sympathizers.
France has been pushing for the swift deployment of an African Union-backed force, the International Support Mission to Mali (Afisma), to take control of Malian towns.
On Tuesday, international donors meeting in Ethiopia pledged $455.53 million for Afisma and for other projects.
African leaders say the overall budget could be around $950 million.
France’s Foreign Minister Laurent Fabius told the meeting impressive progress had been made but that this did not mean the danger was over.
Laurent Fabius also said credible elections in Mali would be vital to achieving sustainable peace in the country.
Mali’s interim President Dioncounda Traore said on Tuesday that he wanted to hold “transparent and credible” elections by July 31.
French-led troops in Mali have taken control of the northern town of Gao, France’s defence ministry has said.
Town of Gao was previously a stronghold of Islamist fighters after it was seized by an alliance of Tuareg rebels and Islamists last April.
French-led troops moved into Gao itself after earlier securing the airport and a strategic bridge to the south.
French officials said troops from neighboring Niger and Chad would now move into the town to help secure it.
They also suggested that government control was already being restored, with the mayor of Gao’s returning on Saturday after being ousted by the Islamist takeover.
There was no official death toll from the offensive, but the French army said “dozens” of Islamist fighters were killed in the overnight operations, without any casualties on the French and Malian side.
After a punishing series of air strikes on jihadist positions in Gao, Malian and French forces took first the airport and then the bridge over the river Niger, before being able to confirm they had taken control of the whole of the town.
Malian officials spoke of scenes of joy on the streets of Gao, but also of some looting.
Gao’s mayor, who has been in the capital Bamako since the town fell to the Islamists early last year, has been flown back in.
French-led troops in Mali have taken control of the northern town of Gao
Chadian and Nigerian forces, meanwhile, are poised to pushed up from the Nigerien border – about 200 km to the south – in order to reinforce the French and Malians.
French-led troops are also reported to be advancing on the town of Lere to the west.
It all appears to confirm a picture of rolling successes for the French and Malians, as they retake the main population centres of the north, says the BBC’s Hugh Schofield in Paris.
The fall of Gao, northern Mali’s most populous town, marks a significant advance for French and Malian troops.
Islamists seized a vast area of northern Mali last year and have imposed strict Sharia, or Islamic law, on its inhabitants.
France intervened militarily on January 11 to stop them advancing further south.
It has already deployed 2,500 soldiers on the ground in Mali as well as launching air strikes.
With the capture of Gao, the French are increasingly confident of pushing the Islamists out of all the major population centres in the north, says our correspondent.
The other major northern towns of Kidal and Timbuktu remain in Islamist hands. But, French Prime Minister Jean-Marc Ayrault said the historic town of Timbuktu – an important symbol which has also been under Islamist control for most of the last year – should also soon be retaken.
The French are confident that this phase of the campaign will soon be over, adds our correspondent, though of course the vast desert hinterland offers the Islamists endless opportunities to retreat and regroup.
The UN refugee agency says more than 7,000 civilians have fled to neighboring countries since 10 January to escape the fighting.
In a statement earlier, Defence Minister Jean-Yves Le Drian confirmed that 3,700 French troops were engaged in Operation Serval, 2,500 of them on Malian soil.
Gao was one of the first rebel-held areas to be targeted by air-strikes after France decided to intervene in its former colony, a decision which took many by surprise.
A UN-backed international force had not been expected in the west African state until the autumn.
Several African countries have pledged military aid to help the Malian government win back control of the north.
On Friday the African Union asked the UN Security Council to authorize immediate logistical help to allow the 6,000-strong force to deploy quickly.
It also recommended civilian observers to monitor the human rights situation in the areas which have come back under the control of the Malian government. Human rights groups have accused the Malian army of committing serious abuses.