The "Don't Ask, Don't Tell" policy was first established in 1993
The highest court in the US has decided not to hear an appeal from a soldier who was dismissed from the US army for being openly gay.
Under the military's "Don't Ask, Don't Tell" policy, people who are openly homosexual are barred from service.
Capt James Pietrangelo II appealed to the Supreme Court to rule that the policy was unconstitutional.
President Barack Obama promised in his election campaign to overturn the policy, but has yet to do so.
Capt Pietrangelo's appeal was opposed by the US government, which argued in papers submitted to the court that the ban was "rationally related to the government's legitimate interest in military discipline and cohesion".
The Supreme Court offered no explanation for its decision.
'Not bad news'
The "Don't Ask, Don't Tell" policy was first established in 1993 by President Bill Clinton.
Mr Clinton had wanted to lift the existing ban on gay people serving in the military, but after facing stiff opposition in Congress opted for a compromise whereby gay soldiers could continue to serve as long as they did not disclose their sexuality publicly.
Gay rights activists vowed to continue to campaign for an end to the ban, despite the court's ruling.
"We don't see that at all as bad news for repeal," said Kevin Nix, spokesman for the Servicemembers Legal Defense Network.
"What happened today puts the ball back into the court of Congress and the White House to repeal the law, and that's where we think it should be right now."