Manning, 28, who is serving a 35-year sentence for passing data to WikiLeaks, began her hunger strike on Friday.
"I am unendingly relieved that the military is finally doing the right thing. I applaud them for that. This is all that I wanted - for them to let me be me," The Guardian cited Manning's statement.
In July, Manning attempted suicide over the government's denial of appropriate treatment for her gender dysphoria- a condition in which a person feels their physical gender is different from what he or she identifies with.
While the US Army has refrained from commenting, Chase Strangio the ACLU lawyer representing her, called it "a monumental day".
"Thankfully the government has recognised its constitutional obligation to provide Chelsea with the medical care that she needs," BBC quoted him as saying.
Arrested originally as Bradley Manning, she was convicted in 2013 of six Espionage Act violations and 14 other offences for leaking more than 700,000 secret military and State Department documents and some battlefield videos.
In November last year, she announced she was suing the Army after being forced to have the men's regulation two-inch prison haircut.
Serving her sentence at the all-male Fort Leavenworth military facility in Kansas, Manning says she has identified as a woman since childhood and had been receiving access to hormone therapy, speech therapy and cosmetics while in prison, The Daily Mail reported.
