Exiled whistleblower Edward Snowden's hopes of being pardoned by the United States government have been dashed after the White House said his actions in leaking secret National Security Agency files to the media was "dangerous" and compromised national security.

The White House's online "We the People" petition allows Americans to create campaigns that the Obama administration will address if a minimum of 100,000 people sign their agreement. The "Pardon Edward Snowden" petition was created just over two years ago – in June 2013 shortly after Snowden began releasing the NSA files and was charged by the US with espionage – and has amassed 167,955 signatures. 

The petition simply states: "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."

President Barack Obama's homeland security and counterterrorism advisor, Lisa Monaco, responded to the petition by saying that because of his actions in revealing mass surveillance programmes operated by the NSA – chiefly monitoring Americans' phone calls and internet activities – he would not be pardoned. 

"Mr 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. 

She said that rather than hand over confidential government material to the media, if he had wanted to carry out an act of civil disobedience, Snowden should have done what many others who have issues with the government have done – protest the mass surveillance, speak up about it and challenge the authorities about the spying programme. 

“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,” Monaco said. 

Earlier this year, some aspects of the NSA spying were ruled illegal, and subsequently lawmakers acted to halt its hoovering up of phone records – thundering reform that has only been made possible because of Snowden’s leaks. 

Snowden, 32, is currently living in Russia, where he was granted political asylum by President Vladimir Putin.