Cameron pledges to defeat IS 'monsters'

In a statement delivered at his official 10 Downing Street residence on Sunday, Prime Minister Cameron pledged that UK authorities would bring to justice those responsible for beheading David Haines, "no matter how long it takes."

Video of the 44-year-old British aid worker being beheaded by a hooded man with a British accent was posted on the Internet late on Saturday. On Sunday, the British Foreign Office said it had no reason to doubt the authenticity of the footage.

Cameron, speaking after talks with his government's emergency response committee, known as Cobra, said Britain would work with its allies to defeat "Islamic State" (IS) extremists, who have seized large swathes of territory in northern Iraq and Syria.

"Step by step we must drive back, dismantle and ultimately destroy ISIL (IS) and what is stands for. We will do so in a calm, deliberate way but with an iron determination," the prime minister said. "We will not do so on our own, but by working closely with our allies, not just the United States and in Europe, but with our allies in the region."

IS fighters were "not Muslims, they are monsters," he said, while describing the 44-year-old Haines, whose beheading has been claimed by IS, as a "British hero."

'Broad-based strategy' needed

Earlier on Sunday, German Foreign Minister Frank-Walter Steinmeier issued a statement in which he condemning the killing of Haines, saying it was "an abhorrent act of barbaric violence beyond all limits of human civilization."

"The international community needs to resolutely confront this threat to Iraq, the entire region and us too," he added.

Steinmeier also said that a conference on Iraq, to be held in Paris on Monday couldn't come at a better time and that he hoped the international community would be able to come up with a "broad- based and regionally anchored political strategy to confront the threat posed by ISIS (IS)."

A statement released by Chancellor Angela Merkel's office said "the unjustifiable act by terrorists must be punished."

US President Barack Obama has also condemned Haines' beheading and pledged to help bring the perpetrators to justice.

Haines, a former member of the Royal Air Force, had worked for various aid agencies in some of the world's most dangerous places. He had been working for the French-based Agency for Technical Cooperation and Development when he was seized by gunmen in Syria in March, 2013.

pfd/se (AFP, AP, Reuters, dpa)