U.S. President Barack Obama www.foxnews.com

President Barack Obama defended the government’s surveillance programs again this week, comparing the tradeoff between security and privacy to the way Americans submit to security checks at airports. The president's comments, in an interview set to air Monday night on PBS, mark the second time he has gone to bat for the National Security Agency’s secret operations since leaks revealed their existence. But in a concession to concerns raised by the leaks, Obama said he has taken steps to declassify more information and hoped to begin a national discussion on privacy, liberty and "big data."

“What I’ve said, and I continue to believe, is that we don’t have to sacrifice our freedom in order to achieve security,” Obama said, according to a partial transcript procured by BuzzFeed. “That’s a false choice. That doesn’t mean that there are not tradeoffs involved in any given program, in any given action that we take. So all of us make a decision that we go through a whole bunch of security at airports, which when we were growing up that wasn’t the case.”

"I don’t think anybody says we’re no longer free because we have checkpoints at airports," he added.

Obama defended the National Security Agency’s collection of so-called metadata – as he did at a press conference over a week ago – by describing the program as limited and subject to the oversight of both the Foreign Intelligence Surveillance Court and Congress. He stressed, as he and members of the administration have, that NSA cannot listen to the content of anyone’s calls without a separate warrant.

The president also took on a top concern of privacy advocates who are deeply suspicious of the program: the potential for future abuse. Obama denied this was a risk, however, by saying that abuse will not happen because it is “illegal.”

Summarizing these critics, Obama said: “they’ll say, you know, ‘You can — when you start looking at metadata, even if you don’t know the names, you can match it up, if there’s a call to an oncologist, and there’s a call to a lawyer, and — you can pair that up and figure out maybe this person’s dying, and they’re writing their will, and you can yield all this information.’ All of that is true. Except for the fact that for the government, under the program right now, to do that, it would be illegal. We would not be allowed to do that.”

Privacy advocates are unlikely to find this very comforting, however, given the fact that illegal, warrantless wiretapping took place during the Bush administration.

Obama did give ground on the issue of secrecy, however, calling it a “legitimate concern.” To remedy this problem as much as possible, he said he is taking steps to declassify information about the programs that can be made public without compromising the programs. “What I’ve asked the intelligence community to do is see how much of this we can declassify without further compromising the program, number one. And they are in that process of doing so now,” he said.

The president also announced the creation of what he called a “privacy and civil liberties oversight board, made up of independent citizens including some fierce civil libertarians.” He plans to meet with the board and use it as a jumping board to a “national conversation, not only about these two programs, but also the general problem of data, big data sets, because this is not going to be restricted to government entities.”

The interview with PBS’ Charlie Rose was filmed at the White House Sunday.