An Islamic State leader tied to the beheading of American aid worker Peter Kassig has been killed in an airstrike, the US military said Monday.

The US-led coalition on Sunday targeted Abu al-Umarayn and several other ISIS members with the strike in a desert area of southeastern Syria, said Col. Sean Ryan.

The ISIS commander posed an “immediate threat” to coalition forces in the area and was “involved in the killing” of 26-year-old Kassig, as well as linked to the executions of several other prisoners, Ryan said in a statement.

Umarayn is the first ISIS member to be publicly identified as having been involved in Kassig’s execution, although it’s unclear exactly what role he played.

Kassig, a former US Army Ranger medic from Indianapolis, worked as a humanitarian worker and was abducted by ISIS in 2013 as he delivered food to refugees in eastern Syria.

Formerly a Methodist, he converted to Islam while in captivity and changed his name to Abdul-Rahman Kassig. His family pleaded for his safe return in a video message to ISIS.

On Nov. 16, 2014, ISIS posted a video showing bloodthirsty beheader “Jihadi John” standing over a severed head, and the White House confirmed Kassig had been killed.

“Jihadi John,” whose real name was Mohammed Emwazi, was killed in a US-led coalition airstrike in November 2015.

With Post wires