FORT MEADE - US soldier Bradley Manning was sentenced on Wednesday to serve 35 years in a military prison for turning over more than 700,000 classified files to WikiLeaks in the biggest breach of secret data in the nation's history.

U.S. Army Pfc. Bradley Manning is escorted out of a courthouse during his court martial at Fort Meade in Maryland, August, 20, 2013. [Photo/Agencies]

Judge Colonel Denise Lind sentenced the 25-year-old former low-level intelligence analyst to less time behind bars than the 60 years military prosecutors had sought, and said Manning could be eligible for parole in about a decade, after serving one-third of his prison term.

Even that shorter prison term is seen as a strong deterrent to others who may consider exposing US government secrets, according to experts and transparency advocates.

"It's more than 17 times the next-longest sentence ever served" for turning over secret material to the media, said Elizabeth Goitein, co-director of the Liberty and National Security Program at the Brennan Center for Justice. "It is in line with sentences for paid espionage for the enemy."

Manning, in uniform, stood quietly showing no emotion as Lind read his sentence during a brief court proceeding at Fort Meade, Maryland, where his court-martial has been conducted for the last 2-1/2 months.

Lind said Manning would be demoted to private, from private first class, and dishonorably discharged from the US military. Also, that his sentence would be reduced by the three years he has served in prison, plus the 112 days she had already decided to subtract because of the harsh treatment the soldier suffered after his arrest three years ago.

Manning will be imprisoned at the US Disciplinary Barracks in Fort Leavenworth, Kansas.

In 2010, Manning was working as an intelligence analyst in Baghdad when he turned over to WikiLeaks a trove of classified files, diplomatic cables and battlefield accounts that included a 2007 gunsight video of a US Apache helicopter firing at suspected insurgents in Iraq, killing a dozen people including two Reuters news staff.

The documents received intense media attention and landed WikiLeaks and its founder, Julian Assange, in the international spotlight.

During the trial, defense lawyers said Manning had hoped the document release would open Americans' eyes to the wars in Iraq and Afghanistan and provoke a more intense debate. Prosecutors contended that the soldier placed national security at risk by revealing confidential information.

As Manning was escorted out of the courtroom, supporters shouted: "Bradley, we are with you."