NEW YORK (AFP) - A documentary about the US journalist James Foley, who was beheaded by the Islamic State in Iraq and Syria (ISIS) extremist group in 2014, will make its world premiere this month, HBO said on Tuesday (Jan 5).

The premium cable network, which has acquired US TV rights to Jim: The James Foley Story, said the documentary will premiere at the Sundance Film Festival before airing on HBO on Feb 6.

The 40-year-old freelance journalist was captured in Syria in 2012 and killed in August 2014. Video of his murder triggered worldwide outrage.

He had reported for GlobalPost, Agence France-Presse and other outlets from Afghanistan, Libya and Syria.

Directed by Brian Oakes, the documentary tells of Foley's life, death and legacy, HBO said.

"Made with unparalleled access, Jim: The James Foley Story is a harrowing chronicle of bravery, compassion and pain at the dawn of America's war with ISIS," the network added.

The film will debut in the US documentary competition at Sundance, the film festival held in Park City, Utah that opens on Jan 21.

HBO described Oakes as a close childhood friend of Foley.

The film includes interviews with family, friends and fellow journalists and "never-before-heard details" of his captivity revealed by fellow hostages, the network said.

"I made this film to carry on the stories that Jim needed us to know," Oakes said in a statement released by HBO.

"It's important that we understand the significant role of today's conflict journalists and why they risk their lives to tell the world how bad it can be."

Press watchdog Reporters Without Borders said 110 journalists were killed around the world in 2015, including 10 in Syria.

HBO is a subsidiary of Time Warner and its programming is available in more than 60 countries.