President Barack Obama's administration reached a deal with top lawmakers in Congress designed to end a US ban on gays serving openly in the military.
Obama vowed to repeal the "Don't Ask, Don't Tell" policy, which forces gays and lesbians to hide their orientation or face expulsion from the military, and has come under intense pressure from gay rights groups for swift action.
The White House and senior lawmakers said the compromise would be brought up in the House of Representatives, possibly as early as this week, but the law would not change until after the military completes an implementation review.
US Defense Secretary Robert Gates and the chairman of the US Joints Chiefs of Staff, Admiral Michael Mullen, had backed the idea of ending the rule.
They said in April however that they opposed any change to the prohibition in the short term because the military needed to assess how the move would impact the armed forces.
But Peter Orszag, the head of Obama's Office of Management and Budget, said in a letter to key lawmakers on Monday that a compromise to allow the review to be complete before the law is changed would permit movement on the legislation.
The review is not due to be completed until December 1.
The compromise was contained in an amendment drafted by Senator Joseph Lieberman, an independent who votes with Democrats and is a member of the Senate Armed Services Committee.
The amendment provides for a review of the impact on changing the law on readiness, military effectiveness and unit cohesion, and provides that the law will not become law until the review is complete and remedies carried out.
The review will seek the views of troops and military families on the issue, as well as take into account the experience of NATO allies and other armies that permit gays to serve openly.
More than 13,500 service members have been dismissed under the law since it was adopted.
The 1993 law replaced an outright prohibition against homosexuals in the military. Former president Bill Clinton agreed to the compromise policy after meeting stiff resistance from commanders and lawmakers when he proposed allowing gays to serve openly.
The move was warmly welcomed by groups which have campaigned for years for the repeal of "Don't Ask, Don't Tell."
"The White House announcement is a dramatic breakthrough," said Aubrey Sarvis, director of Servicemembers Legal Defense Network.
"President Obama's support and Secretary Gates' buy-in should insure a winning vote, but we are not there yet. The votes still need to be worked and counted."