The president said his administration's stance in a California court case is not about defending traditional marriage, but is instead about defending traditional legal practice.
Justice Department lawyers filed new papers Monday seeking to throw out a lawsuit brought by a gay couple challenging the 1996 Defense of Marriage Act, or DOMA. Gay rights groups say that by doing so, the administration is failing to follow through on campaign promises made by Obama last year to work to repeal the law.
Department lawyers are defending the law "as it traditionally does when acts of Congress are challenged," Obama said in a statement.
The Clinton-era law denies federal recognition of gay marriage and gives states the right to refuse to recognize same-sex marriages performed in other states.
Obama said he plans to work with Congress to repeal the law, and said his administration "will continue to examine and implement measures that will help extend rights and benefits" to lesbian, gay, bisexual, and transgender couples under existing law.
The mixed message got a mixed review from Joe Solmonese, president of the Human Rights Campaign, a gay rights group.
"It is not enough to disavow this discriminatory law, and then wait for Congress or the courts to act," Solmonese said in a statement. "While they contend that it is the DOJ's duty to defend an act of Congress, we contend that it is the administration's duty to defend every citizen from discrimination."