Gay rights groups in the US have complained after the country's top military commander said he believed homosexual acts were "immoral".
US service staff can be dismissed if they reveal themselves as gay
Marine General Peter Pace, Chairman of the Joint Chiefs of Staff, said he backed the Pentagon's "don't ask, don't tell" policy regarding homosexuality.
The policy bans homosexual acts between members of the military.
A gay rights group called the comments "a slap in the face to gay men and women serving with honour and bravery".
Joe Solomonese, president of Human Rights Campaign, said: "What is immoral is to weaken our national security because of personal prejudices."
Under the "don't ask, don't tell" policy, introduced in 1993 to relax a complete ban on gays, commanders are not allowed to enquire about the sexual orientation of their personnel.
Soldiers, sailors and air force staff are not supposed to reveal their homosexuality, and are banned from engaging in homosexual acts.
"I believe homosexual acts between two individuals are immoral and that we should not condone immoral acts," Gen Pace told the Chicago Tribune.
"As an individual, I would not want [acceptance of gay behaviour] to be our policy, just like I would not want it to be our policy that if we were to find out that so-and-so was sleeping with somebody else's wife, that we would just look the other way, which we do not. We prosecute that kind of immoral behaviour," he said.
After the controversy broke out, Gen Pace issued a statement seeking to defuse criticism.
He did not apologise but said he "should have focused more on my support of the policy and less on my personal moral views".
Critics of the "don't ask, don't tell" policy say it is discriminatory and also counterproductive - as it may undermine recruitment as the US military is struggling to maintain forces in Iraq and Afghanistan.
A 2005 government audit said 10,000 troops, including more than 50 specialists in Arabic, have been discharged because of the policy.