French President Nicolas Sarkozy confirmed Monday that the 78-year-old French hostage Michel Germaneau, who was kidnapped in April, has been killed by a North African wing of al-Qaida, according to a declaration by the Elysee Palace.

After a defence and security meeting on the issue, which was attended by Prime Minister Francois Fillon, Foreign Minister Bernard Kouchner, Interior Minister Brice Hortefeux and other concerned high profile officials in the morning, Sarkozy declared the confirmation.

The president denounced the revenge killing was "barbarous" and "odious" act, calling French compatriots to avoid traveling in Sahel region of West Africa.

The al-Qaida African branch, AQMI, said Sunday it has killed the French hostage, a retired engineer, in retaliation for the killing of six of its members in a recent raid by Mauritanian troops supported by French military forces, but the Elysee Palace excluded any confirmation on Sunday evening.

A four-day operation by Mauritanian military targeting al-Qaida militants in the Sahara desert wound up on Saturday, which has killed six fighters of AQMI in a raid on a Mali base on Thursday, Mauritanian security source said.

On Friday, France said it has proved technical and logistical support to the anti-terrorism operation aimed at preventing AQMI attacks on Mauritania, also part of an effort to rescue the long-held French hostage.

In his declaration, Sarkozy vowed that France wouldn't let the killers at large and said to prepare French defence force for due response.