US soldier convicted of leaking more than 750,000 classified documents to the Wikileaks website has been sentenced to 35 years in jail by a military court Wednesday.

Private First Class Bradley Manning had been convicted of 20 out of the 22 charges against him, including violations of the US Espionage Act.

He was found guilty of downloading and leaking 400,000 Pentagon field reports from Iraq and 90,0000 similar documents from Afghanistan, as well as over 250,000 State Department cables.

But military judge Col. Denise Lind acquitted him of the most serious charge of "aiding the enemy," and decreased the maximum sentence he could potentially face from 136 years to 90 years.

Manning will also be dishonourably discharged from the US Army and forfeit some of his wages. The three and a half years he has already served will be included as part of his sentencing.

In a statement at a sentencing hearing last week, Manning apologized for his actions, saying that he realized that he had "hurt people and hurt the United States," but claimed that he hadn't meant to cause so much damage.

"I understood what I was doing was wrong but I didn't appreciate the broader effects of my actions," he insisted. 

Manning has always claimed that his decision to leak classified information was made in order to expose American "wrongdoing" and provoke a public debate over US government policy and conduct.

Prosecutors had been asking for 60 years, but his remorse and appeals for leniency given his fragile emotional state at the time due to a number of personal issues, appear to have been taken into account, resulting in a much more lenient sentence.