The French government has increased security around Paris in response to a message from al Qaeda leader Osama bin Laden threatening to kill French citizens.
The newly released audio tape appears to be authentic, the French Foreign Ministry said Thursday.
Soldiers are guarding the Eiffel Tower and other landmarks in the city of Lights.
In the tape obtained by the Al Jazeera television station, the voice on the tape threatened France because of its presence in Afghanistan and a new law banning Muslim women to wear veils in public.
The Foreign Ministry says the tape's "authenticity can be considered established based on initial verifications."
The message "only confirms that reality of the terror threat," Foreign Ministry spokesman Bernard Valero said.
A series of terror warnings have put France and other European countries on high alert in recent weeks, prompting the U.S. State Department to advise American citizens living or traveling in Europe to take more precautions.
There are about 4,000 French troops deployed in and near Afghanistan. France has also passed a law that will ban the wearing of face-covering burqa-style Muslim veils in public starting in April. Al Qaeda had spoken out against the veil measure before it became law.