Fox News Middle East and terrorism analyst Walid Phares told Jenna Lee on "Happening Now" that the horrific beheadings of 21 Coptic Christians in Libya by ISIS-affiliated militants is a very dangerous prelude to what's to come.

He explained that ISIS being affiliated in Libya - "far from the mother bases of ISIS in Syria and Iraq" - shows that the group "is telling us that ISIS is now successful in what Al Qaeda International wanted to do."

"But there's something else, ISIS is committing genocide," Phares stated. "They are killing poor individuals belonging to communities without being a part of any confrontation. I'm referring to the 21 Coptic Christians who were slaughtered in Libya. ISIS, that branch in Libya, has committed to kill way more, hundreds, maybe thousands." 

Phares said that "this is the beginning of what I call a genocidal jihad, meaning a jihad that we have not seen before."

"No limits, no limitations, no exchange of prisoners, no engagement with any mediation as we used to have in the past with Qatar and others," he explained. "This is unleashed completely, because they feel that they can. Because the international campaign has not been successful at this point in time."

He added that he thinks the U.S. is late in acting against the terrorist group.  

Watch the video above to hear more from Phares on "Happening Now."