French and Chadian troops arrived late Thursday at the town of Aguelhok, 160 kilometres (100 miles) north of Kidal, near Mali's border with Algeria, Malian sources said.
"French and Chadian soldiers have left Kidal and are currently patrolling in Aguelhok," Malian Captain Aliou Toure told AFP.
An official with the administration in Kidal confirmed the report.
"The French and Chadian soldiers left in strength by road. They arrived at Aguelhok and are then heading for Tessalit," said the official.
Both towns have been targetted with repeated French air strikes over the last few days aimed at knocking out the Islamist bases, French military spokesman Colonel Thierry Burkhard said.
The two northern towns lie in the Adrar des Ifoghas massif, in the far northeast, a craggy mountain landscape honeycombed with caves, where the insurgents are believed to have fled with seven French hostages.