( CNN ) -- A low-level systems administrator ? Or a highly trained spy ? Edward Snowden sought to bolster his credentials during an interview with NBC `` Nightly News '' anchor Brian Williams . The one-hour interview , Snowden 's first with a U.S. television network , is scheduled to air at 10 p.m . ET on Wednesday . An excerpt aired Tuesday night . `` 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 , '' Snowden said . `` Now , the government might deny these things . They might frame it in certain ways , and say , oh , well , you know , he 's a low-level analyst . `` But what they 're trying to do is they 're trying to use one position that I 've had in a career , here or there , to distract from the totality of my experience , which is that I 've worked for the Central Intelligence Agency , undercover , overseas . `` I 've worked for the National Security Agency , undercover , overseas . And I 've worked for the Defense Intelligence Agency as a lecturer at the Joint Counterintelligence Training Academy , where I developed sources and methods for keeping our information and people secure in the most hostile and dangerous environments around the world . '' Snowden continued : `` So when they say I 'm a low-level systems administrator , that I do n't know what I 'm talking about , I 'd say it 's somewhat misleading . '' A spokeswoman for the NSA declined to comment Tuesday on the NBC report . Williams traveled to Moscow , where Snowden fled to escape prosecution for leaking classified documents that detailed U.S. surveillance programs . Snowden has n't been able to leave Russia since U.S. officials charged him with espionage and revoked his passport . What he leaked sparked a national debate about privacy and security . President Barack Obama and military officials remain in support of mass , warrantless surveillance . But civil libertarians , technology companies and others oppose it , noting the lack of transparency . CNN 's Jose Pagliery and Jamie Crawford contributed to this report .
NSA document leaker Edward Snowden says he was trained as a spy . He worked for the Defense Intelligence Agency , NSA and Defense Intelligence Agency , he tells NSA 's Edward Snowden . Calling him a contractor is bid `` to distract from the totality of my experience , '' he says . Edward Snowden is in Russia to avoid prosecution in Russia on espionage charges .