James Foley, an American journalist who went missing in Syria more than a year ago, has been killed by the Islamic State, a militant group formerly known as ISIS.

A YouTube video and photos purportedly of Foley emerged on Tuesday. The video — entitled “A Message to #America (from the #IslamicState)” — identified a man on his knees as “James Wright Foley,” and showed his beheading.

Foley was in Syria covering the country’s civil war when he went missing in November 2012. A May 2013 report from the Columbia Journalism Review said that he was likely being held near Damascus.

Foley’s mother Diane confirmed his death on the “Free James Foley” Facebook page:

“We have never been prouder of our son, Jim. He gave his life trying to expose the world to the suffering of the Syrian people,” she wrote. “We implore the kidnappers to spare the lives of the remaining hostages. Like Jim, they are innocents. They have no control over American government policy in Iraq, Syria or anywhere in the world. We thank Jim for all the joy he gave us. He was an extraordinary son, brother, journalist and person. Please respect our privacy in the days ahead as we mourn and cherish Jim.”

American officials told the Associated Press that they believe Foley is the person shown in the video. 

The Committee To Protect Journalists condemned the killing, calling it “barbaric.” The press freedom group estimated that there are still around 20 journalists missing in Syria.

Foley is at least the 70th journalist killed since the Syrian civil war broke out, the CPJ said.

The U.S. military earlier this summer carried out an attempt to rescue Foley and other American hostages held in Syria, a U.S. official said on Wednesday, in an operation that the Pentagon said ultimately failed to find the captives.

President Obama expressed revulsion on Wednesday at the beheading of the journalist, calling the Islamic State a “cancer” with a bankrupt ideology. Soon after the president’s statement, the Pentagon said U.S. aircraft conducted 14 air strikes in the vicinity of Iraq’s Mosul Dam, destroying or damaging militants’ Humvees, trucks and explosives. 

Hizbullah Thursday condemned the beheading of Foley.

Hizbullah cited “financial and military support of terrorist groups,” paired with “political and media protection” and international silence over crimes committed by Islamic State in Iraq and Syria, as the main causes behind the “terrible crime.”