Obama warns of jihadist ‘cancer’ as US reveals failed rescue

“Their victims are overwhelmingly Muslim and no faith teaches people to massacre innocents,” he said, dismissing the IS claim to represent the aspirations of a global Muslim caliphate.

“No just God would stand for what they did yesterday and what they do every single day,” he declared.

“We will be vigilant and we will be relentless… From governments and peoples across the Middle East, there has to be a common effort to extract this cancer so it does not spread.”

US intelligence believes the video is genuine, and the British government held a crisis meeting to launch an investigation because Foley’s executioner spoke English with a London accent.

“We have not identified the individual responsible, but from what we have seen, it looks increasingly likely that it is a British citizen,” Prime Minister David Cameron told reporters. “This is deeply shocking.”

Foley’s parents, John and Diane, appeared on the lawn of their home in New Hampshire to pay tribute to their son — the oldest of five adult children — and call for other hostages to be released.

“Jim would never want us to hate or be bitter. We cannot do that and we are just so very proud of Jimmy and we are praying for the strength to love like he did,” Diane said.

US Central Command said 14 air strikes had been carried out on IS targets in Iraq in the 24 hours since the video was released.

The United Nations and Europe’s top powers condemned the killing, and France warned the world faces the “most serious international situation” since 2001, the year of the September 11 attacks.

In a significant shift from its usual policy, Germany said it was ready to send weapons to support Iraqi Kurds against IS.

In June, the group then known as the Islamic State in Iraq and the Levant declared the dawn of a Muslim caliphate and seized control of a swath of eastern Syria and northern Iraq.

This month, Obama reacted by ordering US warplanes to counter threats to US personnel in the Kurdish regional capital Arbil or to civilian refugees from Iraqi religious minority groups.

He has insisted the scope of the strikes would remain limited, but Iraqi officials and observers have argued that only foreign intervention could turn the tide on jihadist expansion in Iraq.

Shiite militias, federal soldiers, Kurdish troops and Sunni Arab tribes have been battling IS for weeks in some areas but have been unable to clinch a decisive victory.