WASHINGTON - President Obama signaled to gay-rights activists yesterday that he was listening to their desire for greater equality in "a more perfect union." But he did not give them even close to everything they wanted, bringing to the surface an anger that has been growing against the president.

"We all have to acknowledge this is only one step," Obama said in the Oval Office, where he signed a memorandum extending some benefits, such as visitation or dependent-care rights, to same-sex couples.

But the president's critics - and there were many - saw the incremental move to expand gay rights as little more than pandering to a reliably Democratic voting bloc, with the primary aim not of making policy more fair but of cutting short a fund-raising boycott.

"When a president tells you he's going to be different, you believe him," said John Aravosis, a Washington-based gay activist. "It's not that he didn't follow through on his promises; he stabbed us in the back."

Obama has refused to take any concrete steps toward a repeal of a policy that bans gays and lesbians from serving openly in the military, even though as a candidate he pledged to scrap the Clinton-era rules. He similarly has refused to step in and block the dismissal of gays and lesbians who face courts-martial for disclosing their sexual orientation.

Obama said he wanted to see the Defense of Marriage Act repealed and in its place a law that would give the partners of gay and lesbian federal employees health insurance and survivor benefits, among other things.

"I believe it's discriminatory, I think it interferes with states' rights, and we will work with Congress to overturn it," Obama pledged, flanked by lawmakers and advocates.

Without that repeal, Obama's ultimate goal of extending health benefits would have to wait. Even those who joined Obama at the signing recognized it was only a first step to achieve what they were promised.

"The community has been growing frustrated and the administration has been working on this since Day One," said Joe Solmonese, the president of the Human Rights Campaign, the nation's largest gay-rights group.

Trying to quell that anger, Obama approved small changes in benefits available to same-sex couples. For instance, employees' domestic partners can be added to a government insurance program that pays for long-term conditions, such as Alzheimer's disease. They also can take sick leave to care for a sick partner or nonbiological child.

But health-care benefits remain forbidden by Congress.

"People feel they're owed an apology," said Richard Socarides, a New York lawyer who advised President Bill Clinton on gay issues. "People in the gay community feel he over-promised and under-delivered. Now, with over 250 discharges from the military on his watch . . . the grace period is over."