Army Pfc. Bradley Manning's 11 months in solitary confinement was cruel, inhuman and degrading treatment," the UN chief on torture said Monday, though he stopped short of calling it torture. Manning, 25, faces 22 counts, including aiding the enemy after he allegedly released classified documents to WikiLeaks. He was held in solitary confinement for 23 hours a day following his arrest in May 2010 in Iraq, and continuing through his transfer to the Marine Corps Base in Quantico, Va. The confinement, lasting about 11 months, ended upon his transfer to Fort Leavenworth, Kan., on April 20, 2011. When Juan Mendez, special rapporteur on torture and other cruel, inhuman or degrading treatment or punishment, asked Department of Defense officials why Manning was held in such a condition, he was told it was due to the gravity of the crime and for "prevention of harm" - though they did not specify what that meant, citing privacy concerns. "He hasn't been convicted of any crime yet so subjecting him to a very long period of solitary confinement on the basis that he might be found guilty of a crime seems to me to be both a violation of his presumption of innocence but also a violation of his right not to be treated cruelly or inhumanely," Mendez told msnbc.com. The explanations for Manning's solitary confinement were "insufficient," according to Mendez. "That's why I reached the conclusion that the United States government was responsible for having inflicted on him cruel, inhuman and degrading treatment," he said."