Image caption Pte Manning was found not guilty of the most serious charge he faced

A sentencing hearing for US Army Private Bradley Manning has begun at a military court in Maryland.

On Tuesday, he was convicted of 20 charges, including espionage and theft, but acquitted of aiding the enemy.

The sentencing could take weeks, with both the prosecution and defence allowed to call witnesses. Pte Manning faces up to 136 years in prison.

He had admitted passing hundreds of thousands of battlefield reports and diplomatic cables to Wikileaks.

Analysis How much damage did Bradley Manning really do? That issue is at the heart of the sentencing process and also the wider debate over whether to treat the soldier as an ethical whistle-blower or a traitor. Supporters say his disclosures helped highlight abuses in Iraq, Afghanistan and elsewhere, and force a debate on what should be kept secret and wider US foreign policy. Critics say that by divulging confidential contacts between US embassies and individuals living under sometimes repressive regimes, he put people at risk, perhaps forcing some into hiding. They add it had a wider chilling effect on people's willingness to talk to US officials and confidential contacts are a necessary part of diplomacy. What the Manning case has done - along with that of Edward Snowden - is push forward a debate on what the boundaries of secrecy should be and when individuals may reveal what had been classified.

The website's founder Julian Assange said Pte Manning's conviction for spying set a "dangerous precedent", accusing the US authorities of "national security extremism".

Mr Assange described the soldier as the most important journalistic source the world had ever seen, and said the military court's verdict had to be overturned.

'Still under fire'

More than 20 witnesses are expected to be called for the sentencing hearing, which could take weeks.

Analysts say Pte Manning, who did not testify in his defence, could still take the stand during the sentencing phase.

On Wednesday, Maj Ashden Fein, the trial prosecutor, said the Wikileaks disclosures "have impacted the entire system" that allows military intelligence analysts to access classified information.

Pte Manning's defence lawyer is expected to say the soldier never intended to harm US national security, an argument made at length and with apparent success during the trial, as he was acquitted of the most serious charge, aiding the enemy.

On Tuesday, Pte Manning appeared not to react as Judge Col Denise Lind read aloud the verdicts, but his defence lawyer, David Coombs, smiled faintly as he was found not guilty of the most serious charge of aiding the enemy.

Media playback is unsupported on your device Media caption Julian Assange described Bradley Manning as a "quintessential whistleblower"

"We won the battle, now we need to go win the war," Mr Coombs said of the sentencing phase. "Today is a good day, but Bradley is by no means out of the fire."

During the trial the judge stopped both sides from presenting evidence about whether the leaks had endangered national security or US troops in Afghanistan and Iraq, but the prosecution and defence will be able to bring that up at the sentencing hearing.

The judge also limited evidence of Pte Manning's motives. At a pre-trial hearing, he testified that he had leaked the material to expose the "bloodlust" of US forces and the country's diplomatic deceitfulness. He did not believe his actions would harm the country.

World media reaction Editorial in The New York Times "Lurking just behind a military court's conviction of Pfc Bradley Manning... is a national-security apparatus that has metastasized into a vast and largely unchecked exercise of government secrecy and the overzealous prosecution of those who breach it." Ansgar Graw in Germany's Die Welt "After the verdict, an immature youngster with vague dreams of a 'better world' and few thoughts about his own obligations is facing further years in prison. But his military superiors failed at least as much as Bradley Manning." China's People's Net website "Manning has a number of supporters in the United States, who believe that Manning uncovered the most ugly side of foreign policy formulated by American politicians and military leaders." Correspondent on Russia's Rossiya TV "The verdict in the Manning case... is also a signal to all future truth-lovers in America... Even after bursting the boil of secrecy, it is very difficult today to not only change the course of history, but also to awaken society that is not ready to and does not want to hear the truth."

During the court martial, prosecutors said Pte Manning systematically harvested hundreds of thousands of classified documents in order to gain notoriety.

With his training as an intelligence analyst, Pte Manning should have known the leaked documents would become available to al-Qaeda operatives, they argued.

The defence characterised him as a naive young soldier who had become disillusioned during his deployment in Iraq.

His actions, Mr Coombs argued, were those of a whistleblower.

Among the items Pte Manning sent to Wikileaks was graphic footage of an Apache helicopter attack in 2007 that killed a dozen people in the Iraqi capital Baghdad, including a Reuters photographer.

The documents also included 470,000 Iraq and Afghanistan battlefield reports and 250,000 secure state department cables between Washington and embassies around the world.

Pte Manning, an intelligence analyst, was arrested in Iraq in May 2010. He spent weeks in a cell at Camp Arifjan, a US Army installation in Kuwait, before being transferred to the US.