The U.S. military has approved hormone therapy for Chelsea Manning, a former intelligence analyst convicted of leaking national security secrets to WikiLeaks, to make the transition to a woman, a media report said Thursday. The decision is said to mark the first time the military has agreed on providing such treatment to any of its personnel.

Formerly known as Bradley Manning, the soldier was approved for gender reassignment on Feb. 5 by Col. Erica Nelson, the commandant of the Fort Leavenworth Disciplinary Barracks in Kansas, where Manning has been serving a 35-year prison sentence after she was convicted in August 2013 of espionage and other charges for sending classified documents to WikiLeaks, USA Today reported.

“After carefully considering the recommendation that (hormone treatment) is medically appropriate and necessary, and weighing all associated safety and security risks presented, I approve adding (hormone treatment) to Inmate Manning's treatment plan,” Nelson wrote in a memo, obtained by USA Today.

The military decision came after Manning filed a lawsuit in September last year against U.S. Defense Secretary Chuck Hagel and other Department of Defense officials, claiming that she was “denied access to medically necessary treatment” for gender dysphoria, the experience of significant discontent with the biological sex one is assigned at birth.

Although transgender individuals are not allowed to serve in the U.S. military, Manning, 26, cannot be discharged from the service until her prison sentence is over, The Associated Press reported.

According to Mara Keisling, executive director of the Washington-based National Center for Transgender Equality, the U.S. Army is simply fulfilling its obligation by providing Manning with medical care, and failing to treat her medical condition would be “cruel and unusual punishment,” USA Today reported.

The American Civil Liberties Union (ACLU), which represented Manning in the legal proceeding, said in a statement last year that though the military recognized she had gender dysphoria requiring treatment, critical care had been withheld without any medical basis.

"Gender dysphoria is a serious medical condition that requires hormone therapy and changes to gender expression, like growing hair, to live consistently with one’s gender identity as part of accepted standards of care," ACLU said in the statement. "Without necessary treatment, gender dysphoria can cause severe psychological distress, anxiety, and suicidality."