Pope Francis has offered prayerful condolences to the family of Steven Sotloff, a U.S. journalist who was executed earlier this month by militants of the Islamic State.

"(Pope Francis) entrusts Steven's soul to the Lord and offers prayers for you and all who mourn his death," Cardinal Pietro Parolin, Vatican Secretary of State, said in a telegram sent Sept. 5 to the journalist's family on the Pope's behalf.

"Upon you and your loved ones, he invokes the Almighty's blessings of consolation and strength."

Sotloff, 31, disappeared in August 2013 during a trip to Syria. The freelance journalist had worked for the magazines Time and Foreign Policy.

On Sept. 2 the Islamic State released a video showing his beheading; Sotloff's family held a memorial service for him at a Florida synagogue Sept. 5.

Cardinal Parolin said that Pope Francis "urges people everywhere to reject violence, aggression and lack of compassion, and asks each one to pray and work for forgiveness, healing and peace."

Sotloff was seen for the first time since his disappearance in the execution video of James Foley, a U.S. journalist killed by Islamic State forces in August.

Pope Francis called Foley's family soon after that video's release.

The Islamic State said the executions are retaliation for U.S. airstrikes. The militant group has also threatened to kill a British man being held hostage.

The Islamic State, a Sunni Islamist group, emerged earlier this year as one of the rebel groups fighting in the Syrian civil war.

This spring it spread its operations to Iraq, taking control of Mosul and swaths of territory in the country's north and west.

It has now established a caliphate in the territory it controls across Iraq and Syria.

The Islamic State has persecuted all non-Sunni persons in its territory: tens of thousands of Christians, Yazidis, and Shia Muslims have all fled the caliphate.