NEW YORK — Chelsea Manning, who confessed to disclosing archives of secret diplomatic and military documents to WikiLeaks in 2010 and has been incarcerated longer than any other convicted leaker in US history, has formally petitioned President Obama to reduce the remainder of her 35-year sentence to the more than six years she has served.

In a statement accompanying her petition, Manning again said she took “full and complete responsibility’’ for her actions, which she called wrong. She also described her difficult life, including the turmoil she faced at the time of her leaks as she came to grips with gender dysphoria while deployed to Iraq, her treatment in prison, and her multiple suicide attempts.

Manning’s petition was accompanied by letters of support from Daniel Ellsberg, who is famous for leaking a classified history of the Vietnam War known as the Pentagon Papers; Morris Davis, a former military commissions chief prosecutor; and Glenn Greenwald, a legal commentator and journalist who has been an outspoken supporter.

While military prosecutors portrayed Manning — formerly known as Private First Class Bradley Manning — as a traitor, many open-government advocates consider her a whistleblower and a hero.

In interviews, both Davis and Ellsberg said they hoped that Obama would give special consideration to her request.