The US Army private known as Bradley Manning wants to be identified as a woman and plans to undergo hormone therapy.
Manning, who was sentenced to 35 years in military prison Wednesday for leaking classified documents to WikiLeaks, said she has felt like a woman since childhood.
In a letter to NBC's TODAY, she wrote: “I am Chelsea Manning. I am female. Given the way that I feel, and have felt since childhood, I want to begin hormone therapy as soon as possible. I hope that you will support me in this transition.”
“I also request that, starting today, you refer to me by my new name and use the feminine pronoun (except in official mail to the confinement facility),” the statement continued. “I look forward to receiving letters from supporters and having the opportunity to write back.”
She signed the letter "Chelsea E. Manning."
More from GlobalPost: Bradley Manning sentenced to 35 years in prison for WikiLeaks case
Manning's defense team had already raised issues about her gender identity struggle and said it may have played a role in why she leaked the documents to WikiLeaks.
It is unclear what Manning's decision means about her prison stay and if authorities would allow her to pursue hormone therapy in jail.
Manning was found guilty of 20 charges, including espionage and theft. She leaked over 700,000 documents to the website WikiLeaks in 2010 while she was a military intelligence analyst in Iraq.
The massive leak of classified information — one of the largest in US history — meant that Manning faced a maximum sentence of 90 years in prison.
She could be up for military parole as early as seven years.