Governments should not mess around when it comes to negotiations with the Islamic State, warns war journalist John Cantlie in his fifth video.

Extremist group Islamic State of Iraq and Syria (ISIS) has release another propaganda video  featuring its longtime prisoner only days after Cantlie's father succumbed to pneumonia. He has been in ISIS' custody for nearly two years.

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In the six-minute broadcast, Cantlie introduces himself as "a British citizen abandoned by my own government". He sought to reveal some uncomfortable truths that have resulted to a series of publicized executions.

A good chunk of the transcript criticized the British and the U.S.' stance against negotiations. Both governments have remained stonewalled, despite other countries agreeing to fulfill conditions for release.

"We saw 16 other citizens from six European countries go home," said Cantlie. "How was this allowed to happen?"

For those who are left behind, he says it is not exactly "a bad life". He gives off the impression that ISIS treats its prisoners well--using words like "community" and "harmony" to describe their current state--as long as they do not do "something stupid".

The British prisoner recounted how those who have tried to escape were waterboarded, just as Muslim prisoners are waterboarded by their American captors.

In the video, Cantlie also reads a selection of e-mails allegedly exchanged between ISIS and family members of some captives, who have expressed frustrations over the governments' refusal to help.

In the absence of negotiations, ISIS told its remaining prisoners that they were worthless to their governments. Cantlie and the rest held on to their hopes.

The British photojournalist signs off with a confirmation that a sixth video is underway. In that one, he will be talking about a failed rescue mission and will be explaining how one soldier was worth five prisoners while they were worth "none."

Cantlie, 43, has worked for British newspapers the Telegraph and the Sunday Times. He was abducted in 2012 along with James Foley, upon his return to Syria to see the fighters who freed him the first time.

In August, ISIS filmed and posted the beheading of American journalists Foley and Steven Sotloff, and British volunteers David Haines and Alan Henning.

TagsJohn Cantlie, British prisoner, ISIS, ISIL, ISIS video, ISIS propaganda, beheading