ISIS militants had demanded $132.5M for James Foley release

LONDON (KABC) -- As the hunt continues for the militant seen in the James Foley beheading video, a U.S. official told the Associated Press that the militants had demanded a ransom for Foley's release.

The Islamic State militants wanted 100 million Euros -- or $132.5 million -- in emails to Foley's family in New Hampshire. U.S. policy prohibits the government negotiating with terrorists, including paying ransom.

Authorities are using voice recognition software and other technology to identify the masked jihadi seen in the gruesome video.

Prime Minister David Cameron has said the man is likely British, and based on his accent, experts say he may be from the London area. Investigators will make a voice print of the speaker and compare it to recordings of known suspects.

British spy agencies have access to voice-recognition technology that can try to match features of the killer's voice to a pre-existing recording, such as an online video or intercepted phone call.

ABC News Interactive: ISIS Trail of Terror

The U.S. continued to pound the terrorist group with air strikes over the past 24 hours, hitting trucks and Humvees used by ISIS in northern Iraq.

Special operations troops were sent to Syria this summer on a secret mission to rescue American hostages held by Islamic State extremists, including Foley, but they did not find them, the Obama administration said Wednesday.

Officials said the rescue mission was authorized after intelligence agencies believed they had identified the location inside Syria where the hostages were being held. But the hostages had been moved from that location, and special operations forces engaged in a firefight with the militants before departing.

The FBI now handling the Foley case, and agents stress the need to keep the terrorist group on the defensive with more military strikes.

"Syria and over into Iraq, that area has become a safe haven and a training ground for some of the world's worst people," said FBI Director James Comey. "There are thousands of terrorists now in Syria and in Iraq from all over the world."

The international police agency Interpol is calling for a globally coordinated effort to stem the tide of international fighters joining the Islamic State group.