Holder says the records seizure was justified as part of an investigation into a "grave" national security leak that he says "put the American people at risk."
Federal officials have said investigators are trying to hunt down the sources for a May 7, 2012, AP story that disclosed details of a CIA operation in Yemen to stop an airliner bomb plot around the anniversary of the killing of Osama bin Laden.
The government obtained the records from April and May of 2012 for more than 20 separate telephone lines assigned to AP and its journalists. AP's top executive called the action a massive and unprecedented intrusion into how news organizations do their work.
The action has created a bipartisan political headache for President Barack Obama, with prominent Republicans and Democrats on Capitol Hill expressing outrage, along with press freedom groups.