The Obama administration has rejected a petition signed by almost 168,000 people calling on it to pardon former intelligence contractor Edward Snowden for leaking US government secrets.
The White House reiterated its tough stance against the exiled fugitive, whom supporters regard as a whistleblower, in response to the petition on its own website.
Lisa Monaco, an adviser on homeland security and counterterrorism, told the AFP news agency that Snowden's "dangerous decision to steal and disclose classified information had severe consequences for the security of our country and the people who work day in and day out to protect it".
She said that Snowden, who has been granted asylum in Russia after he leaked documents on vast US surveillance programmes to journalists, is "running away from the consequences of his actions".
"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," she wrote.
"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."
The US administration has branded Snowden a hacker and a traitor who endangered lives by revealing the extent of the National Security Agency spying programme.
But his revelation that the NSA siphons vast quantities of telephone data from private US citizens struck a cord and Congress has begun to amend once secret laws.
Snowden has been nominated for the Nobel Peace Prize for the second year in a row and has received a string of international awards for free speech and civil liberties.
The petition took up this call.
"Edward Snowden is a national hero and should be immediately issued 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 programmes," it said.
Earlier this year, Congress passed a law which requires the NSA to end bulk data collection. The administration said on Monday the NSA will stop accessing the records on November 29 and would destroy them as soon as possible.