Manning, who held a top-secret security clearance, sent hundreds of thousands of U.S. military documents to WikiLeaks agents so that they could be publicly disclosed — and the website did publish the "vast majority" of those classified records between 2010 and 2011, the indictment alleges.
Those documents allegedly included approximately 800 Guantanamo Bay detainee assessment briefs, a quarter-million State Department cables and 400,000 Iraq War-related reports.
In March 2010, Assange allegedly "agreed to assist Manning in cracking a password stored on United States Department of Defense computers connected to the Secret Internet Protocol Network, a United States government network used for classified documents and communications."
Manning used a Linux operating system to access the password, which would help disguise her activities but was stored on a computer she did not have specific privileges to access, according to the court filing.
Assange was allegedly aware that Manning was providing him information in violation of Army regulations.
On March 8, 2010, before forging the agreement to crack the government password, Manning allegedly told Assange that "after this upload, that's all I really have got left."
The indictment says Assange replied: "Curious eyes never run dry in my experience."
A spokesperson for Manning told NBC News on Thursday that "our legal team is reviewing the language now as it may impact her appeal to the charge of civil contempt," referring to Manning's current legal situation.
"We are confident in Chelsea's legal strategy regarding the grand jury and the appeal and that we may have more we can share soon," the spokesperson added, NBC reported.
Assange had been holed up in the London-based embassy since 2012 in order to avoid an extradition to Sweden related to a sexual assault case. Two years earlier, Sweden had issued a warrant for Assange related to allegations of sexual assault and rape from two women. Those charges were dropped in 2017, though Swedish prosecution agents said that one of the alleged victim's lawyers has requested that the investigation be reopened,
But Assange had refused to leave the embassy for fear of being extradited to the U.S. — a situation that reportedly wore thin for Ecuadorian officials.
Ecuadorian President Lenin Moreno tweeted Thursday that his country had withdrawn Assange's asylum status "after his repeated violations to international conventions and daily-life protocols."
U.K. authorities had entered the London embassy and arrested Assange, who yelled "U.K. must resist" while being loaded into a police wagon. He appeared to be carrying a copy of Gore Vidal's "History of the National Security State" at the time of his arrest.
He was arrested for allegedly breaching U.K. bail conditions, and had been arrested again in a U.S. extradition warrant, according to Metropolitan Police. Multiple outlets reported Thursday that a British court found Assange guilty of jumping bail.
Assange's lawyer, Jen Robinson, did not immediately respond to CNBC's request for comment on the DOJ's announcement of the charge against her client. She had tweeted earlier Thursday that the U.S. warrant had been issued in December 2017.
Robinson vowed Thursday that "we will be contesting and fighting extradition." She added that Assange "will be brought before the court again within the next month."
Read the full indictment against Assange here: