Australian Prime Minister Tony Abbott said Thursday that the Islamic State group's (ISIS) propaganda machine is a death cult. The remarks came during the Countering Violent Extremism summit in Sydney, where tech and world leaders gathered to discuss how to suppress ISIS' successful efforts to recruit new members on social media.

"Daesh is coming, if it can, for every person and for every government with a simple message: 'Submit or die,'" Abbott said, referring to the group also known as ISIS or ISIL. "The declaration of a caliphate, preposterous though it seems, is a brazen claim to universal dominion. You can't negotiate with an entity like this; you can only fight it."

The two-day anti-Islamic State summit counts officials from 27 nations among its attendees, including executives from Twitter, Facebook and Google. "Above all, we need idealistic young people to appreciate that joining this death cult is an utterly misguided and wrong-headed way to express their desire to sacrifice," Abbott said during the meeting, according to CNN.

But Abdul-Rehman Malik, programs manager at Radical Middle Way, an outreach group for young Muslims, said Abbott was fueling ISIS' appeal with his characterization of the militant group. "I think to call [ISIS] a death cult, as the Australian Prime Minister does, is a complete misnomer and it actually feeds in to IS propaganda," he told Lateline. "The propagandists of the Islamic State, when they hear themselves referred to as a death cult hell-bent on global domination, are patting themselves on the back because you know what? You've bought in to their narrative."

U.S. President Barack Obama announced Wednesday he would deploy up to 450 additional military personnel to combat Islamic State fighters in Iraq and Syria. Australia has roughly 530 troops in Iraq fighting ISIS, reported ABC.