Edward Snowden, the National Security Agency (NSA) contractor living in Russia after leaking information about the United States government's mass surveillance programme, has said he would like to return home if he can get a fair trial.

Snowden, who faces espionage charges that could send him to prison for decades, stated his desire to return to the US in an interview with CBS This Morning broadcast on Monday.

“I would like to return to the United States,” said Snowden, whose memoir, "Permanent Record" is to go on sale on Tuesday. "That is the ultimate goal.

"But if I'm gonna spend the rest of my life in prison, the one bottom line demand that we have to agree to is that at least I get a fair trial,” he said.

"And that is the one thing the government has refused to guarantee because they won't provide access to what's called a public interest defence,” he said.

Snowden, who once worked for the Central Intelligence Agency in addition to the NSA, has been living in Russia since leaking thousands of classified documents to the press in 2013 which revealed the scope of US government surveillance after 9/11.

Praised as a whistleblower and a privacy advocate by his defenders, the US accuses Snowden of endangering national security and filed charges against him under the Espionage Act.

Speaking to CBS, Snowden said he was “not asking for a parade".

"I'm not asking for a pardon. I'm not asking for a pass," he said. "What I'm asking for is a fair trial.

"And this is the bottom line that any American should require."

"We don't want people thrown in prison without the jury being able to decide that what they did was right or wrong.

"The government wants to have a different kind of trial," he said. "They want to use special procedures, they want to be able to close the courtroom, they want the public not to be able to go, know what's going on.

"They do not want the jury to be able to consider the motivations — why I did what I did," he said. "Was it better for the United States? Did it benefit us or did it cause harm? They don't want the jury to consider that at all.

"They want the jury strictly to consider whether these actions were lawful or unlawful, not whether they were right or wrong," Snowden said. "And I'm sorry, but that defeats the purpose of a jury trial."