U.S. Chairman of the Joint Chiefs of Staff Admiral Mike Mullen (R) shakes hands with Senator John McCain (R-AZ) before the Senate Arms Services Committee hearing about the "Don't Ask, Don't Tell" policy on gays serving in the military on Capitol
U.S. Chairman of the Joint Chiefs of Staff Admiral Mike Mullen (R) shakes hands with Senator John McCain (R-AZ) before the Senate Arms Services Committee hearing about the "Don't Ask, Don't Tell" policy on gays serving in the military on Capitol Hill in Washington December 2, 2010. REUTERS

The top Republican lawmaker on a key U.S. military oversight committee, while leaving open the possibility of eventually dropping his opposition to the repeal of the military's ban on openly gay and lesbian soldiers, said doing so at this time would be premature.

Sen. John McCain, R-AZ, cited a survey of service members released Tuesday that showed resistance to dropping the Don't Ask, Don't Tell policy in some segments of the armed forces.

I am not saying this law should never change. I am simply saying that it may be premature to make such a change at this time and in this manner, he said.

McCain's comments came during a hearing of the Senate Armed Services Committee where lawmakers heard testimony from top civilian and military officials about the report, issued nearly 10 months after it was commissioned. The report found that the risk of repealing the policy was low.

The hearings come after a tumultuous time for the policy in recent weeks. A federal court overturned the policy in October, then temporarily reinstated it as legal challenges made their way through the appeals process.

McCain noted that in the survey, 67 percent of Marines and nearly 58 percent of Army soldiers in combat units believed that repeal of the law would have negative consequences on unit cohesion in a field environment or out at sea.

Defense Secretary Robert Gates said those concerns could be mitigated if the military leadership was given proper time for preparation and training of subordinates.

Gates acknowledged that concerns were greatest in units where there were limited numbers of troops such as special operations units, where any loss of members is significant.

However he said the reality is they can't just up and leave since they have enlistment contracts and officers have contracts as well.

During that time I think concerns can be mitigated, Gates said.

Admiral Mike Mullen, the Chairman of the Joint Chiefs of Staff, who is also President Barack Obama's top military advisor, noted that the survey found that the experience of those who served with gays and lesbians, even in combat units, was favorable.

He noted that Marines between the ages of 18 and 24, many of whom have not served with women, have very focused, limited experience,

With time and preparation, I think we can mitigate [concerns], Mullen said.

I couldn't disagree more, McCain replied. He said troops were mature enough to say who they wanted to serve with. I speak from personal experience.

All four witnesses at the hearing argued that uncertainty in the courts - especially over the last two months - about the legality of policy created a sense of urgency about reaching a decision to repeal the law.

My sense of urgency would not be as great were it not for what we went through in October and November, Gates said. It was a very difficult experience for us after being told the law had to change because there had been no training, no preparation.

I'm very worried about the courts, Gates said.

Gates added that, based on the information in the report, he felt Congress could act.