Edward Snowden speaks via video link during a news conference in New York City, Sept. 14, 2016. REUTERS

The Obama administration released a list of 200 people who will receive pardons and commutations on Tuesday. That list included Chelsea Manning, who leaked 700,000 military documents to Wikileaks, and was eventually sentenced to 35 years in prison in 2013. But one other famous leaker was notably absent from Obama's pardon list: Edward Snowden, the former NSA contractor who revealed government spying on American citizens in 2013.

So why did Obama commute Manning's sentence while leaving Snowden a wanted man?

In 2013, federal prosecutors charged Snowden with "unauthorized communication of national defense information" and "willful communication of classified intelligence information to an unauthorized person" under the 1917 Espionage Act. He would face at least 30 years in prison if convicted in U.S. courts. He fled to Russia in 2013, where he has been living ever since. On Wednesday, the Russian government announced it had extended Snowden's ability to remain in the country until 2020.

Snowden has not denied that he leaked classified documents to journalists that detailed how the U.S. government gathered metadata on the communications of American citizens, created a program called "Prism" that allowed it to gather data through backdoors in internet companies like Google and Facebook, collected phone records from phone companies and bugged foreign embassies, among other revelations.

"It is clear that in the wake of 2013, the laws of our nation changed,” Snowden told the Guardian in September. “Congress, the courts and the president all changed their policies as a result of these disclosures.”

Both Amnesty International and the ACLU have called on Obama to pardon Snowden, and more than a million people signed a petition urging the president grant Snowden clemency. While technically Snowden is a leaker, many consider him a whistleblower who revealed illegal actions of the U.S. government. In 2016, his story was turned into a film by Oliver Stone.

But while Snowden is often linked to Manning, the White House said the two cases are very different.

"Chelsea Manning is somebody who went through the military criminal justice process, was exposed to due process, was found guilty, was sentenced for her crimes, and she acknowledged wrongdoing,” White House spokesman Josh Earnest said last week. “Mr. Snowden fled into the arms of an adversary, and has sought refuge in a country that most recently made a concerted effort to undermine confidence in our democracy.”

Earnest also said Tuesday that Snowden hadn't filed paperwork to seek clemency.

While Snowden is still a fugitive, Manning has already served seven years of her 35-year sentence in a federal prison. During those years in a male prison, Manning, who was born Bradley, struggled with gender identity issues, once going on a hunger strike in order to win consultation with a surgeon to discuss gender reassignment surgery. She has twice attempted suicide in prison and has been sentenced to solitary confinement.

Snowden, however, has never appeared before U.S. authorities. In November, Obama told a German newspaper that he couldn't "pardon somebody who hasn't gone before a court and presented themselves."

However, that's not entirely true. Obama could pardon Snowden -- Gerald Ford pardoned Richard Nixon before he was even indicted -- but it seems now that he simply won't.