The Obama administration said Tuesday it will not pardon Edward Snowden for leaking thousands of classified intelligence documents to journalists.

In a response to a petition published in early June, the administration said it would not drop espionage charges against the whistleblower.

Just shy of 168,000 people signed the petition calling on the former NSA contractor to be "issued a a full, free, and absolute pardon for any crimes he has committed or may have committed related to blowing the whistle on secret NSA surveillance programs."

But the administration had some harsh words for the Snowden supporters.

United States Homeland Security Advisor Lisa Monaco, who issued the response to the petition on behalf of the administration, admitted that while Americans feel "strongly" about the issue, Snowden's "dangerous" decision to leak programs used by the intelligence community harmed national security.

She added:

"If he felt his actions were consistent with civil disobedience, then he should do what those who have taken issue with their own government do: Challenge it, speak out, engage in a constructive act of protest, and -- importantly -- accept the consequences of his actions. He should come home to the United States, and be judged by a jury of his peers -- not hide behind the cover of an authoritarian regime. Right now, he's running away from the consequences of his actions."

The administration has repeatedly struggled to quantify exactly how Snowden has harmed national security.

Monaco's statement did not, however, note that more than two years following his leaks first debuted in UK and US media, members of Congress successfully changed the law to rein in the National Security Agency's (NSA) surveillance powers following the disclosures.

The NSA came under heavy fire for bulk collection of data, hacking into networks of private companies, and conducting operations seen by many to violate Fourth Amendment protections against unreasonable searches and seizures.

Companies have complained that the activities by the NSA, such as implementing backdoors and weaknesses in software and encryption, are harming their businesses in crucial growth markets, including China.

Snowden, who currently resides in Russia after fleeing the US for Hong Kong, has told journalists that he is willing to return to the US, but only to a fair trial. The Espionage Act, which Snowden faces prosecution under, does not allow defendants to raise a defense in a US court.