President Barack Obama instructed Attorney General Eric Holder on Thursday to review Justice Department guidelines for leak investigations, meet with media organizations and report back to him by mid-July.

In a speech to the National Defense University, Obama addressed the uproar over his administration's numerous leak investigations, saying he is "troubled" that the inquiries might "chill" investigative journalism. But he also emphasized that certain information must remain secret to protect national security.

"As commander in chief, I believe we must keep information secret that protects our operations and our people in the field," Obama said. "To do so, we must enforce consequences for those who break the law and breach their commitment to protect classified information. But a free press is also essential for our democracy."