Central Investigative Agency (CIA) Director John Brennan has warned that the Islamic State (IS) has "snowballed" beyond Iraq and Syria, adding that at least 20,000 jihadists from over 90 countries have joined the ranks of the terror group, several thousand of them from Western nations, including the United States.
While addressing the Council on Foreign Relations in New York on Friday, Brennan cautioned that if left "unchecked," the group would pose a serious threat to not just Syria and Iraq but also to the wider region and beyond, including the U.S. and its allies, reported Fox News.
He added that the IS took advantage of "new technology" to coordinate operations, attract new recruits, disseminate propaganda and urge supporters to carry out attacks in their name.
The CIA chief also warned that the group had grown in size to about 20,000 members and pointed towards the recent pledge of allegiance to IS by Nigeria-based Boko Haram.
Brennan noted that the battle to take on the terror outfit will be a long-drawn struggle and would require "patience and determination."
His statements differ from the claims made by the Obama administration as recently as last month assessing the progress against IS.