A man claiming to be al-Qaida leader Osama Bin Laden has said in an audio message that the release of French hostages depends on the withdrawal of French troops from Afghanistan.
The message, broadcast by al-Jazeera Friday, said the French people will pay a "high price" for President Nicholas Sarkozy's policies.
He said Mr. Sarkozy's refusal to remove troops from Afghanistan is a "green light" to kill hostages.
Extremists are holding at least eight French hostages, five believed to be held in Niger, two in Afghanistan and one in Somalia.
French foreign ministry spokesman Bernard Valero said Friday that France is determined to continue its efforts in Afghanistan, despite threats in the message.
Valero also said France is working to authenticate the audio tape.
France has nearly 4,000 troops in Afghanistan as part of NATO's international coalition forces.
This is the second audio message purportedly from bin Laden that has targeted France.
In October, al-Jazeera broadcast a message threatening to retaliate against France for its policies on Muslims.
The al-Qaida leader is believed to be hiding in the mountainous border area of Afghanistan and Pakistan.
The African wing of al-Qaida, al-Qaida in the Islamic Maghreb, has claimed responsibility for the kidnapping of five French nationals in Niger last year, and the abductions of two Frenchmen in Niger in early January. The two French hostages were later killed during a failed attempt to rescue them.
Some information for this report was provided by AP, AFP and Reuters.