CIA Director John Brennan warns that the suicide attack at Turkey's Ataturk airport, in which three assailants killed at least 41 people, could be a precursor to Daesh, also known as the Islamic State, attacks in America.Brennan,, explains that the terrorist group has expanded their efforts to attack overseas."I am worried from the standpoint of an intelligence professional who looks at the capabilities of Daesh … and their determination to kill as many as people as possible and to carry out attacks abroad," Brennan said in an exclusive interview. "I'd be surprised if Daesh is not trying to carry out that kind of attack in the United States."A video proclaiming support for the Islamic State released recently showed landmarks in San Francisco and Las Vegas as possible targets for "lone-wolf" attacks, though the FBI hasn't confirmed the video's validity, and doesn't consider it a credible threat,revealed in early June that the United Cyber Caliphate, a group that supports Islamic State, sent a "kill list" of almost 8,000 names and addresses of Americans, calling for lone-wolf extremists to "kill them strongly to take revenge for Muslims."According to the Central Intelligence Agency chief, one of the biggest obstacles to stopping Islamic State is Syria's President Bashar Assad, who Brennan claims "is in a better and stronger position" today than he was a year ago, is largely because of Russian intervention in the Syrian civil war."The Russians sometimes want their cake and eat it too as far as having the cooperation with us against terrorists but not wanting to do anything that's going to lead to a political settlement that will have a more durable future as a far as a political agreement," he said.When asked about presumptive Republican presidential nominee Donald Trump's anti-Muslim statements, Brennan avoided outright criticism, but said that "some political quarters" in America provide material for extremist propaganda. The CIA chief also avoided directly answering whether he would provide Trump with classified intelligence briefings, as is usually the case with the major party candidates, if Trump were nominated at the GOP convention next month."The agency will carry out its responsibilities as appropriate in the aftermath of the conventions," Brennan said.