Washington  - US President Barack Obama on Wednesday extended some benefits for government workers to same-sex partners in a bid to give them greater equality.

Obama signed a presidential memorandum that would provide limited health care and financial benefits that are currently denied to gay couples and domestic partners. The State Department last month announced a similar gesture for its employees.

"Many of our government's hard-working, dedicated, and patriotic public servants have long been denied basic rights that their colleagues enjoy for one simple reason - the people that they love are of the same sex," Obama said.

The memorandum "marks a historic step towards the changes we seek," Obama said.

Rights groups welcomed the new gesture but said it did not go far enough. They urged Obama to fulfill his campaign promise to repeal a 1996 law that bars same-sex couples from getting full benefits and prevents the federal government from recognizing same-sex marriages.

"Today's presidential signature is the first brick in paving what is a long path toward equality for gay, lesbian, bisexual and transgender Americans," said Joe Solmonese, president of the Human Rights Campaign, the country's largest lobby group for gay rights.

Obama has been at odds with the gay rights community over his opposition to same-sex marriage, a rallying cry for the movement, though he has supported civil unions that give gay couples equal benefits under the law.

Obama said the memorandum was only a "first step" and he would work with Congress to get the 1996 Defence of Marriage Act overturned.

The long-simmering issue of same-sex marriage is both politically and morally charged in the US. In last November's elections, California, Arizona and Florida passed gay marriage bans. In Arkansas, voters passed a law depriving gays of the right to adopt children.

On the opposite side, Vermont, Iowa, Massachusetts and Connecticut allow same-sex marriage. (dpa)