The 25-year-old, who has been sentenced to 35 years in prison for leaking classified documents to WikiLeaks, revealed the plans in a statement to NBC.
“I am Chelsea Manning,” Manning said.
“I am a female.”
“Given the way that I feel and have felt since childhood, I want to begin hormone therapy as soon as possible,” Manning said.
“I also request that starting today you refer to me by my new name and use the feminine pronoun.”
The statement was signed Chelsea E. Manning.
The soldier’s struggles with identity were key to his defence in his court martial, the BBC reported.
His team said the army missed warning signs that he was struggling with gender identity issues, such as when he sent bosses an email saying he wanted to be a woman, with a photograph of himself wearing makeup and a blonde wig.