Robert Gates, the US Defence Secretary, will take the first concrete steps toward lifting the ban on openly homosexual men serving in the military when he begins a year-long review.
According to US officials, the senior-level study will be co-chaired by a top-ranked civilian and a senior uniformed officer. It would recommend the best way to go about lifting the ban.
While the review is likely to take a year to complete, and even more time to implement, its initiation will advance President Barack Obama's goal of repealing the ban and bringing a divisive issue for the military and Congress back to the fore.
Mr Gates will testify before the Senate on the issue, alongside Adm Mike Mullen, the chairman of the Joint Chiefs of Staff, on Tuesday. Both were expected to make their most far-reaching statements on the ban widely known as "don't ask, don't tell".
"I think you'll see efforts on a number of fronts over the course of the next many months ... to address what the president promised," said the White House press secretary, Robert Gibbs.
One office said Mr Gates and Adm Mullen will outline a more lenient standard for enforcing the current ban. The interim policy would make it harder for a third party to turn in a gay service member and would raise the standard for evidence that the service member is gay before the person could be dismissed.
Under the 1993 law, engaging in homosexual conduct - even if you don't tell anyone - can be enough to earn dismissal. The law was intended as a compromise between President Bill Clinton, who wanted to lift the military's ban on gays entirely, and a reluctant Congress and military that said doing so would threaten order.
David Hall, a former air force sergeant, said he was discharged in 2002 after someone else reported that he was gay.
"That ended it," said Hall, who now works for a gay rights advocacy group. "Just like that, based off what one person said, ended my dream of getting to fly planes."
Repeal of the ban has been opposed by some senior members of the Joint Chiefs of Staff and by some reluctant congressional Democrats.
Last year, the Defence Department dismissed the fewest number of service members for violating its "don't ask, don't tell" policy than it had in more than a decade.
According to figures released by the Pentagon, 428 service members in 2009 were dismissed for being openly gay compared with 619 in 2008. In 1997, 997 service members were dismissed. The number fluctuated over the next decade, with fewer troops discharged after the war in Afghanistan began.
The 2009 figure reflects Obama's first year in office after declaring opposition to the policy, even though he did little to reverse it.
Overall, more than 10,900 troops have been dismissed under the policy.