Edward Snowden says he worked as a spy for the US ‘at all levels’

Fugitive US whistle-blower Edward Snowden "trained as a spy" and worked "undercover overseas" for intelligence agencies, he told NBC News.

In his first interview with US media, Snowden hit back at claims that he was merely a low-level contractor, saying he worked "at all levels - from the bottom on the ground, all the way to the top."

Snowden, who has been charged in the US with espionage, was granted asylum by Russia in August last year after shaking the American intelligence establishment to its core with a series of leaks on mass surveillance in the US and around the world.

In the interview, Snowden defended himself against claims minimising his intelligence experience before he stole and leaked classified documents revealing the NSA's programme of phone and internet surveillance.

"I was trained as a spy in sort of the traditional sense of the word in that I lived and worked undercover overseas - pretending to work in a job that I'm not - and even being assigned a name that was not mine," he said.

He said he had worked covertly as "a technical expert" for the Central Intelligence Agency and the National Security Agency, as well as a trainer for the Defence Intelligence Agency.

"I don't work with people. I don't recruit agents. What I do is I put systems to work for the United States. And I've done that at all levels - from the bottom on the ground all the way to the top," he claimed.