Chief of the National Security Agency Admiral Michael Rogers on Tuesday defended the agency's use of a facial-recognition program and said that it follows legal procedures while using the method on U.S. citizens, even as he played down the possibility that Edward Snowden is a foreign spy.

Rogers' defense was in response to a report on Saturday by the New York Times, which said that the organization was intercepting “millions of images per day” of people in various locations. Rogers defended the NSA's actions by saying that it was an effort to counter terrorism, and added that the procedure could only be undertaken for U.S. citizens if certain legal parameters were met.

“We do not do this in some unilateral basis against U.S. citizens,” Rogers at a conference on cyber security in Washington, according to Bloomberg, adding: “We have very specific restrictions when it comes to U.S. persons.”

Rogers said, according to Bloomberg, that the organization does not use passports or vehicle databases, and tried to clear the air about how the agency collects data and to bring more clarity to the public on its role in combating terrorism. A Senate meeting scheduled for next week will also clarify a framework for the agency's functions and set privacy limits for the investigation of citizens, while ensuring that its efforts at countering terrorism are not unduly curtailed.

“In broad terms, we have to stop what we’re doing if we come to the realization that somebody we’re monitoring or tracking has a U.S. connection that we were unaware of,” Rogers said, according to Bloomberg, adding: “We have to assess the situation and if we think there is a legal basis for this and we have to get the legal authority or justification.”

Rogers also observed that it's becoming increasingly difficult for people to maintain their anonymity in the digital realm and added, according to Bloomberg: “We have framed this debate much too narrow from my perspective. This is much bigger than the National Security Agency.”

Speaking about Snowden's efforts at outing the NSA's global spying activities, Rogers said that while he disagreed with Snowden’s decisions, he may not be a foreign spy as alleged by many NSA partners, The Guardian reported.

“Could he have? Possibly. Do I believe that’s the case? Probably not,” Rogers said, according to The Guardian, which cited a NBC interview last week, adding: “He clearly believes in what he’s doing. I question that; I don’t agree with it. I fundamentally disagree with what he did. I believe it was wrong, I believe it was illegal.”