ASPEN, Colo. (Reuters) - Central Intelligence Agency Director John Brennan said on Friday he was not optimistic about the future of Syria.

"I don't know whether or not Syria can be put back together again," Brennan told the annual Aspen Security Forum. His comments were a rare public acknowledgement by a top U.S. official that Syria may not survive a five-year civil war in its current state.

(Reporting by Warren Strobel; Writing by Eric Walsh)