Pfc. Bradley Manning offered guilty pleas to 10 of the 22 counts he has been charged with for his role in leaking documents to the website WikiLeaks.
Manning, though, pleaded not guilty to the most serious charge of aiding the enemy.
If accepted, Manning would face up to 20 years in prison for the 10 counts to which he pleaded guilty. Those counts were for sending hundreds of thousands of classified documents to WikiLeaks, according to the AP.
The charge of aiding the enemy, which he did not plead guilty to, could lead to a life sentence if convicted.
Manning spoke for more than an hour in the courtroom Thursday as he read from a 35-page statement explaining why he leaked the documents to WikiLeaks, according to Reuters.
“I believe that if the general public ... had access to the information ... this could spark a domestic debate as to the role of the military and foreign policy in general," Manning said, according to Reuters.
"I felt I accomplished something that would allow me to have a clear conscience," he said.
Manning has been jailed for more than 1,000 days for his alleged role in the massive leaking of documents to WikiLeaks.
--This report was updated at 1:44 p.m.