PETERSON AIR FORCE BASE, Colo. (AP) — On the eve of a vote to end the military ban on openly gay service members, the nation's top uniformed military officer repeated his support Wednesday for repealing the "don't ask, don't tell" policy.

"Personal opinion? I believe it's time. I believe we need to change it," Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, told about 500 service members at Peterson Air Force Base.

However, Mullen stressed that the change had not yet been approved. And if it is, he said he wouldn't make any final determinations on how to implement it until the military studies the issue and gets input from troops.

The Senate Armed Services Committee plans to vote Thursday on overturning the ban. The proposal would overturn the ban but allow the military to decide when and how to implement any changes.

Mullen talked about the likely repeal in a question-and-answer session with the troops.

His visit sparked a response from GOP Rep. Doug Lamborn, who represents the area. Lamborn told reporters a repeal of the ban should not even be considered until the military has completed its study.

Earlier in the day, Mullen addressed 1,001 graduating cadets at the U.S. Air Force Academy in nearby Colorado Springs. He didn't refer directly to the gay ban but urged the new officers to have the "strength of character" to support whatever decision is made.

At Peterson, Mullen also fielded questions about strategies involved in Afghanistan and the drug war in Mexico, and being used to prevent soldier suicides.

After an hour, Mullen suggested they talk about "the elephant in the room" — the pending congressional vote on "don't ask, don't tell."

When no one raised a hand with a question, Mullen nodded to television cameras filming the session.

"Oh, nobody wants to be seen on camera asking about it," Mullen said.

After a hearty laugh from the service members. Mullen explained his position.