NSA Whistleblower Edward Snowden: "The U.S. Constitution Has Been Violated on a Massive Scale"

Edward Snowden, the former National Security Agency contractor who last year leaked documents about classified government surveillance programs, told NBC News' Brian Williamsthat he considers himself a patriot in an interview that aired Wednesday night.

"I think patriot is a word that's thrown around so much that it can be devalued nowadays," Snowden said during the sit-down, which was his first on an American television network. "Being a patriot doesn't mean prioritizing service to government above all else. Being a patriot means knowing when to protect your country, knowing when to protect your Constitution, knowing when to protect your countrymen, from the violations of and encroachments of adversaries. And those adversaries don't have to be foreign countries."

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Snowden, who has been living in Russia despite not speaking the language, says he's been "trapped" there by the U.S. government, which revoked his passport and blocked him from flying to Latin America via Cuba. "It's really frustrating for someone who's working so hard to expand the domain of our rights and our privacy to end up stuck in a place where those rights are being challenged in ways that I would consider deeply unfair," he said.

Snowden, who says he's been watching old episodes of The Wire as he adapts to living overseas, says he wants to return to the United States. "I miss my family," he told Williams. "I miss my home. I miss my colleagues."

Secretary of State John Kerry delivered a televised response to Snowden's remarks, calling him a "coward" and a "traitor," and saying that Snowden is welcome to return to the United States whenever he chooses. "He has betrayed his country," Kerry said. "If he wants to come home tomorrow to face the music, he can do so. ... If Mr. Snowden wants to come back to the United States today, we'll have him on a flight today."

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Snowden's response? "When people say, 'Why don't you face the music?' I say, 'You have to understand the music is not an open court and a fair trial,'" he told Williams. "You are not allowed to argue based on all the evidence in your favor because that evidence may be classified."

In spite of everything, Snowden said he doesn't regret his decision to act as a whistleblower. "The reality is, the situation determined that this needed to be told to the public," he told Williams. "The Constitution of the United States had been violated on a massive scale."

What do you think of Snowden's remarks? Watch excerpts from his interview below, and see the entire conversation via NBC News.