Extremists linked to the so-called "Daesh" [ISIL] group beheaded a French citizen abducted in Algeria in a video posted online on Wednesday, after Paris rejected their demand to halt air strikes in Iraq.

Herve Gourdel was kidnapped on Sunday by the so-called "Jund al-Khilifa" ["Soldiers of the "Caliphate""] in Algeria.

His beheading followed France's rejection of the group's 24-hour ultimatum to halt air raids in Iraq -- part of a US-led campaign against Daesh.

Meanwhile, France's President Francois Hollande condemned the "cruel and cowardly" murder of Herve Gourdel and said it would only strengthen France's resolve to pursue its air war against the Daesh extremist group.

Hollande vowed France would not be deterred from continuing its military action.

"This aggression only reinforces my determination," he said, speaking on the sidelines of the UN General Assembly.

He said he would convene a special security meeting on Thursday to discuss Gourdel's murder and vowed to hunt down his killers.

Source: Agencies