U.S. soldier turned whistleblower Chelsea Manning has been released from prison.

Manning, previously known as Bradley, was convicted in 2013 of leaking a cache of American military and diplomatic papers to Wikileaks and had originally been sentenced to 35 years in prison - meaning she would have been behind bars until 2045.

Former US President Barack Obama reduced Manning's remaining prison sentence so that she could be released early before he left office earlier this year.

A US Army spokesperson confirmed that the former low-level army intelligence analyst had left Fort Leavenworth Disciplinary Barracks in Kansas early on Wednesday morning.

During Manning's trial it emerged that she had copied some 250,000 diplomatic cables from American embassies around the world and hundreds of thousands of military incident logs from the Afghanistan and Iraq wars before disclosing them to Wikileaks.

Shortly after being convicted she revealed that she identified as a woman and changed her name from Bradley to Chelsea.