President Barack Obama suggested in an interview last week that he won't pardon Edward Snowden because the former NSA contractor "hasn't gone before a court," though Snowden's advocates have disputed his reasoning, pointing to historical precedent.

"I can't pardon somebody who hasn't gone before a court and presented themselves, so that's not something that I would comment on at this point," Obama said in an interview with the German newspaper Der Spiegel and public broadcaster ARD. "I think that Mr. Snowden raised some legitimate concerns. How he did it was something that did not follow the procedures and practices of our intelligence community. If everybody took the approach that I make my own decisions about these issues, then it would be very hard to have an organized government or any kind of national security system."

"At the point at which Mr. Snowden wants to present himself before the legal authorities and make his arguments or have his lawyers make his arguments, then I think those issues come into play."

Trump's pick for CIA director has called for Snowden's execution

The interview, published on Friday, marks the first time that Obama has commented on Snowden since the launch of a campaign in September calling for him to be pardoned. Snowden, who faces charges under the Espionage Act for leaking thousands of classified NSA documents in 2013, has said that he should be pardoned because the leaks benefited the public. In 2014, Obama acknowledged that the ensuing debate over national security and privacy "will make us stronger."

Noa Yachot, director of the Pardon Snowden campaign, questioned Obama's reasoning in a blog post published Friday, pointing out that other presidents — including Obama — have pardoned people who were indicted but did not stand trial.

"Richard Nixon hadn’t even been indicted when Gerald Ford issued a 'full, free, and absolute pardon unto Richard Nixon for all offenses against the United States which he, Richard Nixon, has committed or may have committed or taken part in' over the course of his presidency," Yachot wrote. "Nor had the thousands of men who had evaded the Vietnam War draft, who were pardoned unconditionally by Jimmy Carter on his first day in office." Yachot notes that in January, Obama himself pardoned three Iranians who had been charged with sanctions violations as part of the Iran nuclear deal.

"In pardoning Snowden, President Obama would be helping to secure his legacy while sending a powerful message on his way out – that standing up to government abuse is a tradition we should treasure and take with us into the next four years," Yachot added.

If Obama remains unsympathetic to Snowden's plea, his chances seem unlikely to improve under a Donald Trump administration. Kansas congressman Mike Pompeo, whom Trump has selected to run the CIA, has called Snowden a "traitor" and said that he should be executed.