Long prison term for Snowden 'would erode democracy in US'

National Security Agency leaker Edward Snowden says it would "chill speech" and "erode the quality of our democracy" if he serves a long prison term in the United States.

Mr Snowden spoke via a videolink at a New York news conference on Wednesday. Advocates, including Human Rights Watch and Amnesty International, are launching a public campaign to persuade President Barack Obama to pardon him.