After speaking with the family of the late James Foley, President Barack Obama delivered a speech Wednesday about his brutal murder and promised to hold his killers responsible.

On Tuesday, the infamous Iraqi terrorist group known as the Islamic State in Iraq and Syria, or ISIS, released a video of the beheading of Foley, an American journalist who was captured in November 2012 while reporting in northern Syria, reports the New York Daily News.

"The entire world is appalled" by ISIS and their murder of Foley, said President Obama, who appeared visibly angry over the act during his speech in Martha's Vineyard, ABC News reports.

"No just God would stand for what they did yesterday or every single day," the president said at the news conference. "People like this ultimately fail. They fail because the future's won by those who build and not destroy. The world is shaped by people like Jim Foley."

Obama went on to dismiss ISIS as morally bankrupt, saying the group "speaks for no religion. No faith teaches people to massacre innocents."

The president promised to pursue justice for the family of the 40-year-old New Hampshire native.

"The United States of American will continue to do what we must do to protect our people," the president said. "We will be vigilant, and we will be relentless ... to see that justice is done."

Obama confirmed that he spoke earlier with Foley's relatives, telling them that "we are all heartbroken by his loss."

The militants in the video, titled "A Message to #America (from the #IslamicState)," said the beheading was retribution for recent U.S. airstrikes in Iraq. They also threatened to kill another American journalist who is currently trapped in captivity.

U.S. officials say they employed intermediaries from Turkey, Russia and Czech to advocate for his release prior to Foley's execution.