The Department of Justice on Thursday filed new charges against Wikileaks founder Julian Assange, stating that the longtime transparency activist put the U.S. at risk of “serious harm” by releasing secret and classified government documents, the agency announced.

In an 18-count, superseding indictment, Justice Department prosecutors allege that Assange directed former Army intelligence analyst Chelsea Manning in one of the largest compromises of classified information in U.S. history.

ABC: Justice Department unveils 18-count superseding indictment charging WikiLeaks founder Julian Assange with "offenses that relate to Assange’s alleged role in one of the largest compromises of classified information in the history of the United States." pic.twitter.com/HoUB4yMERi — Josh Caplan (@joshdcaplan) May 23, 2019

The new Espionage Act charges go far beyond an initial indictment against Assange made public last month that accused him of conspiring with Manning to crack a defense computer password.

The new indictment reads that Assange conspired with Manning to obtain and disclose classified national defense documents, including State Department cables and reports on the wars in Iraq and Afghanistan. Prosecutors say his actions “risked serious harm” to the United States.

“Julian Assange is no journalist. No responsible actor, journalist or otherwise, would purposely publish the names of individuals he or she knew to be confidential sources, exposing them to the gravest of dangers,” Assistant Attorney General John Demers said in a statement.

Barry Pollack, an attorney for Assange, said in a statement to Mother Jones that the latest charges “encouraging sources to provide him truthful information and for publishing that information.”

“These unprecedented charges demonstrate the gravity of the threat the criminal prosecution of Julian Assange poses to all journalists in their endeavor to inform the public about actions that have been taken by the US government,” Pollack added.

Assange is in custody in London after being evicted from the Ecuadorian Embassy in April. The U.S. is seeking his extradition.

The dramatic development comes after Swedish authorities issued a request for a detention order against Assange. Prosecutors in the Scandinavian country relaunched a preliminary probe into the WikiLeaks founder after two Swedish women said he committed sex crimes against them. The charges were dropped in 2017 when the statute of limitations expired.

The Associated Press contributed to this report.