Al - Nusra Front could have as many as 10,000 fighters inside Syria , analyst said . Concern about the group is at an all - time high . The Syrian civil war is expected to top the agenda at the G8 summit this week . With the growing strength and support for al-Nusra , U.S. concerns are growing about its influence to further destabilize Syria and potentially pose a greater regional threat , administration officials have told CNN . The meeting came just after the U.S. announced it will start arming Syrian rebels .
Al - Nusra Front could have as many as 10,000 fighters inside Syria , analyst said . Concern about the group is at an all - time high . The Syrian civil war is expected to top the agenda at the G8 summit this week . The meeting came just after the U.S. announced it will start arming Syrian rebels .