Updated — 5:43 p.m. ET
Eric Holder announced Thursday that he will resign as U.S. Attorney General.
In an announcement in the White House State Dining Room, Holder thanked President Obama for "the opportunity that you gave me to serve and for giving me the greatest honor of my professional life."
"We have been great colleagues, but the bonds between us are much deeper than that," Holder said to Obama in an emotional speech. "In good times and in bad, in things personal and in things professional, you have been there for me. I'm proud to call you my friend."
NPR first reported the news on Thursday morning.
Holder won't disappear from the national stage immediately — he plans to leave the Justice Department once a successor is confirmed, a process that could run into 2015.
A White House official said Thursday that Obama has not decided on a successor.
Holder's resignation comes with a legacy of pushing civil rights advancements and battling Congressional Republicans. In an interview with the New Yorker in February he said he would step down at some point in 2014.
The first black attorney general, Holder was credited with heading to Ferguson, Missouri, and helping to ease tensions after the fatal shooting of an unarmed teenager, Michael Brown, by a white police officer.
"There has been no greater ally in the fight for justice, civil rights, equal rights, and voting rights than Attorney General Holder," Myrlie Evers-Williams, civil rights activist and wife of slain activist Medgar Evers."
But he came under fire during his tenure for pushing to hold the trials of the accused 9/11 plotters in New York City. (The administration later changed course under pressure.) Also, House Republicans voted him in contempt for refusing to hand over documents about the gun-trafficking operation Operation Fast and Furious, which involved the U.S. government sending guns to Mexico that were subsequently used in crimes.
Text of Holder's remarks:
I come to this moment with very mixed emotions: proud of what the men and women of the Department of Justice have accomplished over the last six years, and at the same time, very sad that I will not be a formal part -- a formal part -- of the great things that this Department and this President will accomplish over the next two.
I want to thank you, Mr. President, for the opportunity that you gave me to serve and for giving me the greatest honor of my professional life. We have been great colleagues, but the bonds between us are much deeper than that. In good times and in bad, in things personal and in things professional, you have been there for me. I'm proud to call you my friend.
I'm also grateful for the support you have given me and the Department as we have made real the visions that you and I have always shared. I often think of those early talks between us, about our belief that we might help to craft a more perfect union. Work remains to be done, but our list of accomplishments is real.
Over the last six years, our administration -- your administration -- has made historic gains in realizing the principles of the founding documents and fought to protect the most sacred of American rights, the right to vote.
We have begun to realize the promise of equality for our LGBT brothers and sisters and their families. We have begun to significantly reform our criminal justice system and reconnect those who bravely serve in law enforcement with the communities that they protect.
We have kept faith with our belief in the power of the greatest judicial system the world has ever known to fairly and effectively adjudicate any cases that are brought before it, including those that involve the security of the nation that we both love so dearly.
We have taken steps to protect the environment and make more fair the rules by which our commercial enterprises operate. And we have held accountable those who would harm the American people -- either through violent means or the misuse of economic or political power.
I have loved the Department of Justice ever since as a young boy I watched Robert Kennedy prove during the Civil Rights Movement how the Department can and must always be a force for that which is right. I hope that I have done honor to the faith that you have placed in me, Mr. President, and to the legacy of all those who have served before me.
I would also like to thank the Vice President, who I have known for so many years, and in whom I have found great wisdom, unwavering support, and a shared vision of what America can and should be.
I want to recognize my good friend Valerie Jarrett, whom I've been fortunate to work with from the beginning of what started as an improbable, idealistic effort by a young senator from Illinois, who we were both right to believe would achieve greatness.
I've had the opportunity to serve in your distinguished Cabinet and worked with a White House Chief of Staff -- a White House staff ably led by Denis McDonough that has done much to make real the promise of our democracy. And each of the men and women who I have come to know will be lifelong friends.
Whatever my accomplishments, they could not have been achieved without the love, support and guidance of two people who are not here with me today. My parents, Eric and Miriam Holder, nurtured me and my accomplished brother, William, and made us believe in the value of individual effort and the greatness of this nation.
My time in public service, which now comes to an end, would not have been possible without the sacrifices too often unfair made by the best three kids a father could ask for. Thank you, Maya. Thank you, Brooke. And thank you, Buddy.
And finally, I want to thank the woman who sacrificed the most and allowed me to follow my dreams. She is the foundation of all that our family is, and the basis of all that I have become. My wife, Sharon, is the unsung hero. And she is my life partner. Thank you for all that you have done. I love you.
In the months ahead, I will leave the Department of Justice, but I will never -- I will never -- leave the work. I will continue to serve and try to find ways to make our nation even more true to its founding ideals.
I want to thank the dedicated public servants who form the backbone of the United States Department of Justice for their tireless work over the past six years, for the efforts they will continue, and for the progress that they made and that will outlast us all.
And I want to thank you all for joining me on a journey that now moves in another direction, but that will always be guided by the pursuit of justice and aimed at the North Star.