Speaking at the University of Louisville, Biden called Mubarak's decision to relinquish power an "historic day for the people of Egypt" and a "pivotal moment in history."
Biden's midday speech was delayed about a half-hour after Mubarak's sudden decision to shift authority to the military following waves of mass protests demanding his resignation.
Near the start of his 50-minute talk, Biden said the aspirations of the Egyptian protesters must be met.
"The transition that's taking place must be an irreversible change in a negotiated path toward democracy," he said.
Biden limited his remarks about the developments in the Middle Eastern country, saying he didn't want to get ahead of President Barack Obama, who planned to speak Friday afternoon from the White House.
The vice president shared the stage with Senate Republican leader Mitch McConnell, who did not comment on the dramatic events in Egypt while introducing him.
Biden's speech was part of the McConnell Center's lecture series at the university. The vice president spoke to a crowd of about 1,200 faculty, staff, students and members of the general public.