President Barack Obama has directed federal agencies to extend benefits for same-sex partners of federal employees, including child care services, expanded family and medical leave.

Obama's directive covers only benefits that can be extended under existing law. Lawmakers would be required to approve other benefits such as healthcare.

"While this memorandum is an important step on the path to equality, my administration continues to be prevented by existing Federal law from providing same-sex domestic partners with the full range of benefits enjoyed by heterosexual married couples," Obama said.

"The act defines marriage as a legal union between one man and one woman," the White House said in a statement earlier this week.

Though this is the president's latest step to further gay rights, activists criticize him for not moving quickly enough to provide complete equality for same-sex couples.