Assange was arrested by British police from the Ecuadorean embassy in London last month.
The U.S. Justice Department on Thursday announced 17 new criminal charges against WikiLeaks founder Julian Assange, saying he unlawfully published the names of classified sources and conspired and assisted ex-Army intelligence analyst Chelsea Manning in obtaining access to classified information.
The superseding indictment comes a little more than a month after the Justice Department unsealed a narrower criminal case against Assange.
He was initially charged with conspiring with Manning to gain access to a government computer as part of a 2010 leak by WikiLeaks of hundreds of thousands of U.S. military reports about the wars in Afghanistan and Iraq, some of which exposed potential war crimes.
In response to new charges, Wikileaks tweeted: "This is madness. It is the end of national security journalism and the first amendment."
Assange is currently fighting extradition to the U.S., after Ecuador revoked his seven-year asylum in the country's London embassy back in April. He was arrested on April 11 by British police.
He is now serving a 50-week sentence in a London jail for skipping bail when he fled to the Ecuadorean embassy in 2012.