"The honest to God answer is I just don’t know,” Biden said when asked about 2016 during the Eizenstat lecture at the Ahavath Achim Synagogue in Atlanta.
The VP said he is still weighing whether he and his family have the “emotional energy” for another campaign -- especially after Biden's son Beau passed away.
It’s the first time the vice president has publicly discussed a 2016 bid since speculation about his presidential ambitions grew over the past month.
The vice president has spent the past several weeks huddling with advisers and family to discuss a potential third run for the White House.
Biden noted that others have raised questions about whether he can raise enough money or construct an organization to execute a successful campaign. But he wondered if he could get through a presidential campaign and if he and his family could make the "arduous commitment."
Sources close to Biden have said he would likely make a decision by the end of the month. Tonight, the vice president said, "there's no way to put a timetable on this."
"If I can reach that conclusion that we can do it in a fashion that would still make it viable, I will not hesitate to do it," he said. "I have to be honest with you...I can't look you straight in the eye and say now I know I can do it."