Participants carry a large rainbow flag towards the U.S. Capitol during a gay rights demonstration in Washington October 11, 2009. REUTERS/Molly Riley

WASHINGTON (Reuters) - President Barack Obama on Wednesday expanded benefits for same-sex partners of federal employees, a move likely to be welcomed by gay rights activists who have questioned his commitment to their causes.

Obama said he had directed government agencies to offer a number of new benefits to the families of gay and lesbian federal employees, including family assistance services, hardship transfers and relocation expenses.

His directive builds on a move he made last year to offer healthcare benefits, sick leave and medical evacuation for same-sex partners of federal employees.

Obama said in a statement that while his directive was an “important step on the path to equality,” existing federal law prevented him from taking further action to provide same-sex domestic partners with the same benefits offered to heterosexual married couples.

He called on Congress to swiftly pass a measure that would address that discrepancy.

Gay rights activists, who were big supporters of Obama during his 2008 presidential campaign, have criticized him for not moving fast enough to repeal the “don’t ask, don’t tell” policy that prevents gay men and women from serving openly in the military.