Paris: Paris vowed on Tuesday there would be no negotiation with militants who kidnapped a French hiker in Algeria, as the local army raced against time to find him before his threatened execution.

Algerian military planes were combing the mountainous eastern Tizi Ouzou region backed by elite anti-terrorist troops in a desperate bid to find 55-year-old Herve Pierre Gourdel, a security source said.

The kidnapping was claimed by Jund Al Khilifa (Soldiers of the Caliphate), a group linked to Islamic State of Iraq and the Levant (Isil) militants who vowed to kill the hostage by Tuesday night if Paris did not stop air strikes in Iraq.

The French government confirmed as authentic a video posted by the group showing the white-haired and bespectacled hostage squatting on the ground flanked by two hooded men clutching Kalashnikov assault rifles.

However Paris refused to be cowed by the threat against Gourdel and Prime Minister Manuel Valls insisted the country would press on with air strikes alongside the United States.

Valls told French radio there would be “no discussion, no negotiation and we will never give in to blackmail. Even if we are of course very worried after the authentication of this video.”

“If we give in, if we retreat an inch, we will be handing them victory,” Valls told Europe 1 radio while on a visit to Germany.

The video surfaced shortly after Isil issued a statement urging Muslims to kill Westerners whose nations have joined a campaign to battle the militant group, in particular Americans and French.

The United States has built a broad coalition of more than 50 nations to fight Isil, after the jihadists seized large parts of Syria and Iraq and committed widespread atrocities including beheadings and crucifixions.

On Friday, France conducted its first air strikes in Iraq.

“These strikes, this engagement will of course continue,” promised Valls.

The country “cannot be scared of those who threaten it in this way,” he said, but added: “I want to convince our compatriots ... that we have never been up against such a threat, in France and in Europe.”

However while the United States launched strikes against the Islamic State jihadists in Syria, France has said it will not do so.

Paris had however been prepared to strike military targets in Syria after an August 2013 sarin attack, before the US backed off after the regime agreed to turn over its chemical arsenal.

“In Iraq, we are taking part in the aerial operation. In Syria we are helping the opposition. That is our position and it has not changed,” Foreign Minister Laurent Fabius said in New York on Monday.

In a YouTube video posted on Monday night — Jund Al Khilifa, which has pledged allegiance to Isil — threatened to kill Gourdel within 24 hours unless Paris halts its air strikes.

“It is up to Hollande, president of the criminal French state, to halt the attacks on the Islamic State [Isil] within 24 hours of this statement,” one of his kidnappers says in the video, threatening to kill him otherwise.

Gourdel lives in the southern city of Nice and works as a mountain guide. He arrived in Algeria on Saturday and was seized a day later while hiking with Algerian friends.

The 55-year-old is a passionate photographer who has travelled widely to countries such as Morocco, Jordan and Nepal.

“I have always wanted to capture these incredible landscapes. It was in the Moroccan Atlas mountains that I began to progress. I wanted to bring back images of the people who lived there,” he explains on his professional site.

Gourdel’s 82-year-old mother told the Express newspaper the kidnapping was “an ordeal for us.”

She last heard from her son on Sunday.

“Everything was fine, he said he was going for a two-day hike and that it would be hard to reach him,” she said.

Several French citizens have been targeted by kidnappers in the Sahel in recent years, the base of Al Qaida in the Islamic Maghreb, or AQIM.

AQIM is currently holding another French citizen, Serge Lazarevic who was kidnapped in November 2011. Experts say the group has collected over $120 million (Dh440 million) in ransom payments in the previous eight years.