British Prime Minister David Cameron insisted that ISIS militants "are monsters" and "not Muslims" following the release of a video showing the beheading of British aid worker David Haines.
"Islam is a religion of peace," Cameron said on Sunday, according to CNN. "They are not Muslim, they are monsters."
"It falls to the government and to each and every one of us to drain this poison from our society and to take on this warped ideology that is radicalizing some of our young people," he added, referring to the reports that hundreds of young British men have joined the terror group.
Britain has condemned the murder of Haines, the father of two who served at a refugee camp in Syria before he was taken by jihadists.
The video mirrors previous videos released by ISIS showing the beheadings of American journalists James Foley and Steven Sotloff. In each of the videos, including the latest, a militant from the terror group threatens the Western powers to stay out of its operations in Iraq and Syria.
The masked executioner in the video, speaking with a British accent, says: "This British man has to pay the price for your promise, Cameron, to arm the Peshmerga [Kurdish] against the Islamic State. If you, Cameron, persist in fighting the Islamic State then you, like your master Obama, will have the blood of your people on your hands."
The 44-year-old aid worker is also forced to read a statement, where he says:
"I would like to declare that I hold you, David Cameron, entirely responsible for my execution. You entered voluntarily into a coalition with the United States against the Islamic State just as your predecessor Tony Blair did, following a trend against our British prime ministers who can't find the courage to say 'no' to the Americans."
Cameron declared, however, that the footage "will not lead Britain to shirk our responsibility" in the initiative against ISIS, and said that "it must strengthen our resolve."
"We have to confront this menace," the British PM continued. "Step by step we must drive back, dismantle, and ultimately destroy ISIL and what it stands for." Together with allies, he said, "we will do so in a calm, deliberate way but with an iron determination."
His comments that ISIS militants are not Muslims reflects what President Barack Obama said in a major speech last week, when he stated that the jihadist group is not Islamic.
"Now let's make two things clear: ISIL is not Islamic. No religion condones the killing of innocents, and the vast majority of ISIL's victims have been Muslim," Obama said on Wednesday. "ISIL is a terrorist organization, pure and simple. And it has no vision other than the slaughter of all who stand in its way."
The president's assertion has been criticized in a number of circles, including by atheist author Sam Harris, who said that the connection between Islam and ISIS is clear.
"In drawing a connection between the doctrine of Islam and jihadist violence, I am talking about ideas and their consequences, not about 1.5 billion nominal Muslims, many of whom do not take their religion very seriously," Harris stated.
"Understanding and criticizing the doctrine of Islam — and finding some way to inspire Muslims to reform it — is one of the most important challenges the civilized world now faces. But the task isn't as simple as discrediting the false doctrines of Muslim 'extremists,' because most of their views are not false by the light of scripture. A hatred of infidels is arguably the central message of the Quran."
Daniel Pipes, the founder and president of the Middle East Forum, a Philadelphia-based research institute, also said in reference to Obama's claim:
"In the end, though, neither U.S. presidents nor Islamist apologists fool people. Anyone with eyes and ears realizes that the Islamic State, like the Taliban and al-Qaeda before it, is 100 percent Islamic," he added.