Alexanda Kotey, 36, and El Shafee Elsheikh, 32, will stand trial in the US for their involvement in the executions of Western hostages in Syria.
El Shafee Elsheikh and Alexander Kotey appeared by video link in a Virginia court to hear the accusations against them.
The pair are accused of killing a number of Western captives, including Britons Alan Henning and David Haine