In a "Second Message to America" Islamic State beheads US reporter Steven Sotloff.
The video warns governments to back off from "this evil alliance of America against the Islamic State".
Sotloff, 31, disappeared while reporting in Syria in August 2013. His apparent kidnap was not widely reported until he appeared on a video released last month by the ISIS.
In the video, British citizen David Cawthorne Haines is shown as the next beheading victim.