John Cantlie
Kidnapped British journalist John Cantlie as seen in the first video released by ISIS on Sept. 18, 2014. ISIS Video Screenshot

The Sunni Muslim militant group ISIS has released a new video Thursday showing captured British journalist John Cantlie, saying he promises to reveal the 'truth behind the Islamic State.'

The video -- whose authenticity could not be independently verified -- shows Cantlie, who was a reporter for The Sunday Telegraph, The Sun and The Sunday Times, wearing a orange jumpsuit, sitting at a desk in a darkened room. He explains that in a series of videos he will dispel some of the 'manipulated truths' told by the Western media.

Cantlie was captured after he went to Syria in November 2012.

While the video has no visual indication of date, Cantlie does say "nearly two years later" after referring to his capture in November 2012, and he says that the Islamic State has grown to Eastern Syria and Western Iraq, suggesting the video is relatively new. In addition, Cantlie makes specific reference to recent military developments: "Why is it that governments appear so keen to get involved in yet another unwinnable conflict?" he says.

Towards the end of the video, Cantlie says that he will explain why European citizens have been released by ISIS while U.S. and UK citizens were not. U.S. journalists James Foley and Steven Sotloff and British aid worker David Haines have been executed on camera by ISIS.

"There is time to change this seemingly inevitable sequence of events, but only if you, the public, act now," says Cantlie, before the video fades to black.