With growing criticism from frustrated gay rights advocates, Obama made what he called a first step to ending discrimination against same-sex couples.
He also reaffirmed his opposition to the federal Defense of Marriage Act and vowed to work with Congress to repeal it.
Conservative groups see Obama's move as an attempt to appease faithful voters and potential donors.
"President Obama's ... Executive Order uses taxpayer money to placate an angry portion of his base at the expense of the rule of law," commented Family Research Council President Tony Perkins in a statement. "Ironically, Mr. Obama has pursued an aggressive pro-homosexual agenda – but his actions to date are, apparently, insufficient for the radical homosexuals pushing their extreme demands."
While some gay rights groups welcomed Wednesday's move, others were less convinced and left wanting more.
"When a president tells you he's going to be different, you believe him," said John Aravosis, a Washington-based gay activist, to The Associated Press. "It's not that he didn't follow through on his promises, he stabbed us in the back."
Aravosis, along with many other gay rights activists, felt betrayed by Obama when the Justice Department filed a motion last week to dismiss a gay couple's lawsuit against DOMA. They were outraged by the department's arguments defending DOMA – which defines marriage as a legal union between one man and one woman for purposes of all federal laws, and provides that states need not recognize same-sex marriages from another state.
John Berry, the highest-ranking openly gay official in the administration, said the extension of benefits is not in response to any outside pressure and that the administration had been working on it for many months.
The presidential memorandum would allow domestic partners of federal civil service employees to be added to the long-term care insurance program and also allow employees to use sick leave to take care of domestic partners and children.
Although Obama stopped short of providing same-sex couples with full healthcare coverage, which is prohibited under current federal law, FRC's Perkins says the executive order appears to be a violation of DOMA and plans to review it with the group's legal counsel.
Meanwhile, conservative groups are warning Americans about the "unprecedented and underreported" homosexual political agenda of Obama.
"Americans need to know about this full-throated attack by the Obama Administration and its congressional allies on the moral and social order, from marriage to the military to the nation's schools," said Robert Knight, Washington, D.C., correspondent for Coral Ridge Ministries.
"If this agenda triumphs, it will not usher in an era of tolerance, but rather the kind of repression and intolerance toward Christians and other traditionalists that we have seen in Europe and Canada," Knight cautioned. "The eventual outcome would be the criminalization of Christianity."