French Prime Minister Francois Fillon vowed on Tuesday to strengthen operations against the North African wing of al-Qaeda (AQMI) and crack down on the insurgents in the Sahel region there.

Fillon made this remark after the killing of French hostage Michel Germaneau was confirmed on Monday.

"We are at war with al-Qaeda and we've provided military support particularly to the Mauritanian forces, which fight al-Qaeda in the Maghreb, because it represents a threat for all the countries," Fillon told radio Europe 1.

"The fight against terrorism will continue. The fight against al-Qaeda will be reinforced," he added.

France Monday confirmed the killing of 78-year-old French hostage Germaneau by AQMI. Germaneau was kidnapped in April, together with his Algerian company who was released later.

The abductor refused to negotiate on Germaneau's freedom, unless their demand of freeing AQMI members in French prison is met, France said.

The French Military last week provided technical and logistical support to an anti-terrorism raid to free Germaneau. The operation left six insurgents dead, but failed to free the hostage.

Fillon firmly condemned the execution of Germaneau, saying that his death would not remain unpunished.

"We do not revenge, France did not revenge. We have signed agreements with the governments in the region (Sahel) to hunt down the terrorists and to bring them to justice," Fillon noted.

"In France, the terrorist threat is at very high alert level, in the maximum and we will strengthen our efforts to face it," he said.