French officials say they want to get in contact with al-Qaida-linked militants in hopes of gaining the release of five French nationals and two Africans kidnapped in Niger last week.
Defense Minister Herve Morin said Thursday that France has every reason to believe the hostages are still alive and that they probably have been taken to northern Mali.
France has flown search missions over the Sahara in hopes of locating the victims.
North Africa's al-Qaida in the Islamic Maghreb claimed responsibility for the kidnapping. The hostages include two employees of the French nuclear energy firm Areva and five with a subsidiary of the French construction company Vinci.
The group has warned the French government against doing what it described as anything "stupid."
The al-Qaida group has carried out previous kidnappings in the region, including that of a 78-year-old Frenchman who was abducted in Niger in April and later killed.
Some information for this report was provided by AP and AFP.