Washington: A high-ranking ISIS fighter was sentenced on Friday to life imprisonment in the US for his participation in a hostage-taking scheme that resulted in the deaths of four American citizens as well as the deaths of British and Japanese nationals in Syria, according to the US Justice Department.

According to court documents, from November 2012 through Feb. 7, 2015, former British citizen El Shafee Elsheikh, 34, served as a leader in a wide-ranging conspiracy involving the captivity of 26 hostages in Syria.

Elsheikh personally participated in the detention of and hostage negotiations for four American citizens - James Wright Foley, Kayla Jean Mueller, Steven Joel Sotloff, and Peter Edward Kassig - each of whom died as hostages in ISIS custody.

In addition, Elsheikh personally participated in the detention of and hostage negotiations for British, French, Italian, Danish, German, Spanish, Swedish, Belgian, Swiss, and New Zealand nationals.

FBI Deputy Director Paul Abbate said ISIS committed horrific acts against hostages held in Syria and nothing can make up for their suffering and loss. "We will always remember the victims who perished and our thoughts today are especially with the Foley, Mueller, Sotloff, and Kassig families. Today's sentencing demonstrates that those who kill or injure our citizens cannot hide forever," Abbate was quoted as saying in a statement issued by US Justice Department.

According to court documents and evidence presented during trial, Elsheikh and two other ISIS members supervised the terrorist organization's jails and detention facilities at which the hostages were held.

Elsheikh and his co-conspirators engaged in a prolonged pattern of physical and psychological violence against hostages that was meant as an effort to subdue the hostages.

"These actions were also intended to compel the victims' family members and their governments to pay large monetary ransoms for their release, in addition to compelling the U.S. government and other governments to agree to other terms and conditions for the victims' return," the statement said.

According to evidence presented during trial, in addition to physically and psychologically abusing the hostages, Elsheikh and his co-conspirators participated in forcibly exposing the hostages to the murder of other hostages held by ISIS, including a Russian hostage who was killed in or about February 2014 and a Syrian prisoner who was executed in or about April 2014.

After a group of European hostages were forced to witness the execution of the Syrian prisoner, Elsheikh and his co-conspirators returned the hostages to the prison where they were being held with American and British hostages.

According to evidence presented during trial, Elsheikh was part of a group of ISIS members who spoke with British accents and were referred to by the hostages as the "Beatles."

He and his convicted co-conspirator, Alexanda Amon Kotey, 38, were captured together in January 2018 by the Syrian Democratic Forces as they attempted to escape Syria for Turkey. Mohammed Emwazi, who conducted the above-referenced videotaped beheadings, was killed in November 2015 in a U.S. military airstrike in Syria.