WASHINGTON?(UPDATE 2) Top US officials hailed a Senate vote Saturday that will for the first time allow gay men and lesbians to serve openly in the military but said it would take time to implement the bill.

President Barack Obama lauded as an "historic step" the Senate's repeal of the "Don't Ask Don't Tell" policy ? which forced gay troops to keep their sexual orientation secret ? and was expected to sign it into law next week.

But it will only take effect once Obama, Defense Secretary Robert Gates and Chairman of the Joint Chiefs Admiral Mike Mullen ? all of whom supported the bill ? certify that the new regulations will not undermine the military.

"While today's historic vote means that this policy will change, the implementation and certification process will take an additional period of time," US Defense Secretary Robert Gates said.

"In the meantime, the current law and policy will remain in effect."

Mullen also praised the Senate's approval of the bill, saying it "preserves the military's prerogative to implement change in a responsible, deliberate manner.

"More critically, it is the right thing to do. No longer will able men and women who want to serve and sacrifice for their country have to sacrifice their integrity to do so... We will be a better military as a result."

Secretary of State Hillary Clinton, whose husband Bill had enacted the "Don't Ask Don't Tell" policy as a compromise in 1993 when he was president, said the appeal would strengthen US support for human rights internationally.

"This is a historic step forward for all Americans, a step toward a more perfect union and a more perfect reflection of our core values," she said.

"We are committed to universal standards abroad and here at home. Our progress on equality here strengthens our advocacy for human dignity everywhere," she said in a statement.

The head of a group representing gay men and lesbians secretly serving in the military hailed the Senate vote while noting it would still take time before service members could safely reveal themselves.

"OutServe looks forward to the day that repeal of this law is signed by our commander in chief and we can all begin to serve openly and honestly," said the group's co-director, known by the pseudonym JD Smith.

"There will come a moment when it will finally be completely safe to ?come out' and OutServe will be there to support the troops ? gay and straight ? when that day comes, hopefully soon."