The advances by government and French troops left them deployed along the main access routes to the desert redoubts of the Islamist fighters farther north in settlements like Timbuktu and Gao.

Interviewed by the French radio station RFI, Gen. Ibrahima Dahirou Dembele, the Malian Army chief of staff, said his forces were seeking “the total liberation of northern Mali.”

“If the support remains consistent, it won’t take more than a month to free Gao and Timbuktu,” he said, northern cities that have been occupied by the Islamists since early 2012. France has listed the restoration of central government authority across Mali as one of its aims in the campaign.

Agence France-Presse quoted French military officials on Tuesday as saying French warplanes had attacked Islamist command centers near Timbuktu in airstrikes over the past 48 hours. France has said it is aiming to send 2,500 soldiers to Mali, and 2,150 have been deployed so far.

Neighboring Chad has said it will send 2,000 soldiers to join West African forces assembling in support of government and French troops in Mali.

Islamist fighters overran Diabaly a week ago, the closest they have come to Bamako in an aggressive surge this month. Worried that there was little to stop them from rolling into the capital, where many French citizens live, France quickly stepped into the fight, striking the militants at the front lines and bombing their strongholds in the north.

Suddenly, a long-simmering standoff with the Islamist groups holding the north had been transformed into a war involving French forces, precisely the kind of event the West hoped to avoid. American officials have long warned that Western involvement could stir anti-Western sentiment and provoke terrorist attacks, a fear that seemed to be realized when militants stormed a gas facility in Algeria last week, resulting in the deaths of at least 37 foreign hostages.