The US Supreme Court has refused to force the US military to allow openly gay people to serve, while an appeals court considers the issue.
A federal court in California had ruled the "don't ask, don't tell" policy unconstitutional but allowed it to stay in place pending an appeal.
In the latest ruling, the Supreme Court rejected a gay group's request to lift the order allowing the ban to continue.
President Obama wants the ban repealed, but prefers that Congress take action.
Last month, US District Judge Virginia Phillips in San Francisco ruled the "don't ask, don't tell" policy violated gays' right to freedom of speech and equal protection under the law because it effectively prohibited them from speaking about their lives.
She issued an injunction forbidding the Pentagon from enforcing the ban, but an appeals court ruled the ban could stay in place while the Obama administration appeals against the ruling.
Britain, Israel and dozens of other countries allow gay personnel to serve openly, but under the US policy established in 1993, gays may serve in the military but cannot acknowledge their orientation. The military is forbidden to inquire but may expel service members found to be gay.
Though Mr Obama favours repealing the ban, he has said the change should come through legislation, rather than the courts, and has appealed against the rulings.
A Republican-led minority in the US Senate in September blocked debate on a provision to repeal the ban. With the party's numbers in Congress strengthened after the November election, ban opponents see a diminished chance of a repeal.
Meanwhile, the Pentagon is set to release a survey showing most US troops think allowing gays to serve openly in the military would have a minimal effect on US war efforts.