Just as in the civil rights struggles of the 1960s, the stakes in the current generation over same-sex marriage rights "could not be higher," said Holder.
"The Justice Department's role in confronting discrimination must be as aggressive today as it was in Robert Kennedy's time," Holder said of the attorney general who played a leadership role in advancing civil rights.
Human Rights Campaign President Chad Griffin said Holder's "landmark announcement will change the lives of countless committed gay and lesbian couples for the better. While the immediate effect of these policy decisions is that all married gay couples will be treated equally under the law, the long-term effects are more profound. Today, our nation moves closer toward its ideals of equality and fairness for all."
Holder's speech was criticized by the conservative National Organization for Marriage.
"This is just the latest in a series of moves by the Obama administration, and in particular the Department of Justice, to undermine the authority and sovereignty of the states to make their own determinations regulating the institution of marriage," said Brian Brown, the group's president. "The changes being proposed here to a process as universally relevant as the criminal justice system serve as a potent reminder of why it is simply a lie to say that redefining marriage doesn't affect everyone in society."
On Monday, the Justice Department will issue a policy memo to its employees instructing them to give lawful same-sex marriages full and equal recognition, to the greatest extent possible under the law.
Holder's address is the latest application of a Supreme Court ruling that struck down a provision in the Defense of Marriage Act defining marriage as the union of one man and one woman. The decision applies to legally married same-sex couples seeking federal benefits.
After the Supreme Court decision last June, the Treasury Department and the IRS said that all legally married gay couples may file joint federal tax returns, even if they reside in states that do not recognize same-sex marriages. The Defense Department said it would grant military spousal benefits to same-sex couples. The Health and Human Services Department said the Defense of Marriage Act is no longer a bar to states recognizing same-sex marriages under state Medicaid and Children's Health Insurance Programs. The U.S. Office of Personnel Management said it is now able to extend benefits to legally married same-sex spouses of federal employees and annuitants.
Holder told his audience:
The Justice Department will recognize that same-sex spouses of individuals involved in civil and criminal cases should have the same legal rights as all other married couples, including the right to decline to give testimony that might violate the marital privilege. Under this policy, even in states where same-sex marriages are not recognized, the federal government will not use state views as a basis to object to someone in a same-sex marriage from invoking this right.
The U.S. Trustee Program will take the position that same-sex married couples should be eligible to file for bankruptcy jointly and that domestic support obligations should include debts such as alimony owed to a former same-sex spouse.
Federal prisoners in same-sex marriages will be entitled to visitation by a spouse, inmate furloughs during a crisis involving a spouse, escorted trips to attend a spouse's funeral, correspondence with a spouse and compassionate release or reduction in sentence based on an inmate's spouse being incapacitated.