"I don't think there are any sure things in this kind of endeavor, and I wouldn't be honest with you and with the viewers if I didn't convey that," Petraeus told ABC commentator George Stephanopoulos in an interview broadcast today on "Good Morning America."
In his first public comments since the latest WikiLeaks publication of secret international documents, Petraeus also denied recent reports that he threatened to resign over critical comments made by Afghan President Hamid Karzai about the allied forces' battle tactics.
"I've got a military mission. He is the leader of a sovereign country," Petraeus said. "He has a political foundation that he has to maintain. And we do need occasionally, I think, to walk a mile or a kilometer in his shoes and in these mountains to understand the challenge that he has."
After nine years of war, fewer Afghans support American troops, and fewer believe that their presence makes their country safer, according to a recent ABC News/Washington Post poll.