President Barack Obama pledged Wednesday to continue to confront Islamic State militants despite the beheading of an American journalist, in Iraq, standing firm in the face of the militants' threats to kill another hostage — a former University of Central Florida student — unless the U.S. military changes course.

Obama's remarks affirmed that the U.S. would not change its military posture in Iraq in response to the killing of journalist James Foley and threatening to kill another journalist, former UCF student Steven Sotloff.

Since the video was released, the U.S. military has pressed ahead by conducting nearly a dozen airstrikes on Islamic State targets in Iraq.

Calling the Islamic State a cancer, Obama forcefully condemned the group that seized territory in Iraq and Syria, and he called for a vigilant, relentless and global effort to curtail an organization he said is torturing, raping and murdering thousands of people in "cowardly acts of violence."

"ISIL speaks for no religion," Obama said, using an alternative name for the Islamic State. "Their victims are overwhelmingly Muslim, and no faith teaches people to massacre innocents. No just god would stand for what they did yesterday and what they do every single day."

Obama spoke at a media center set up by the White House on Martha's Vineyard in Massachusetts, where Obama is in the second week of his annual summer vacation.