Obama said he could not comment specifically on possible amnesty because Snowden was 'under indictment'

Barack Obama has declined to be drawn into a debate about possible amnesty for Edward Snowden, the whistleblower whose revelations about the NSA have sparked intense internal deliberation about changing US surveillance activities.

In a press conference at the White House, the president distinguished between Snowden’s leaks and the debate those leaks prompted, which he said was “an important conversation we needed to have”, but left open the question of whether he should still be prosecuted.

“The way in which these disclosures happened has been damaging to the United States and damaging to our intelligence capabilities,” he said. “I think that there was a way for us to have this conversation without that damage. As important and as necessary as this debate has been, it’s important to keep in mind this has done unnecessary damage.”

The president would not comment on a suggestion at the weekend by Richard Ledgett, the NSA official investigating the Snowden leaks, that amnesty might be appropriate in exchange for the return of the data Snowden took from the agency.

Obama said he could not comment specifically because Snowden was “under indictment,” something not previously disclosed. While the Justice Department filed a criminal complaint against Snowden on espionage-related charges in June, there has been no public subsequent indictment, although it is possible one exists under gag order.

The Justice Department referred comment on a Snowden indictment to the White House, which did not immediately reply.

Ben Wizner, Snowden's attorney, rejected the president's contention that the debate about the NSA's activities could have taken place without Snowden. "The president said that we could have had this important debate without Snowden, but no one seriously believes we would have," Wizner told the Guardian.

"And now that a federal court and the president’s own review panel have agreed that the NSA’s activities are illegal and unwise, we should be thanking Snowden, not prosecuting him.”