President Obama formally asks Supreme Court to allow gay marriage

Barack Obama has formally asked the US Supreme Court to strike down a 1996 law defining marriage exclusively as a union between a man and a woman.

The request was contained in a legal brief filed with the US court, whose nine justices will next month review whether or not to repeal the federal Defense of Marriage Act, which bans marriage between homosexuals.

The document marks the first time a president has endorsed same-sex marriage rights before the Supreme Court.