Hollande said he would convene a special security meeting at the Elysee palace tomorrow to discuss the latest developments and vowed France would stay the course in fighting Islamists in Iraq.
"This aggression only reinforces my determination" to confront the jihadist threat, Hollande said on the sidelines of the UN General Assembly.
Jund al-Khilifa, or "Soldiers of the Caliphate," claimed to have beheaded the Frenchman abducted in Algeria in a video posted online today.
The apparent 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 IS fighters.
"The perpetrators of this odious crime must be punished," Hollande said.
