FORT MEADE: The US soldier accused of slipping a cache of classified documents to WikiLeaks is expected to take the stand for the first time during a new round of pre-trial hearings that began Tuesday.

Army private Bradley Manning, 24, could spend the rest of his life in prison if convicted of aiding the enemy with the massive leak -- including military logs from Iraq and Afghanistan and sensitive diplomatic cables, that embarrassed Washington and angered US allies.

Manning, surrounded by his legal team, appeared frail as he attended the first day of his latest round of pre-trial hearings due to last until Sunday at the Fort Meade military base near the US capital.

At issue is the treatment he received while he was detained at the military prison in Quantico, Virginia shortly after his arrest in May 2010.

Manning was initially held at a US base in Kuwait after his arrest in Iraq before he was moved to Quantico. He is expected to speak about his detention conditions on Wednesday or Thursday.

The defense has filed an appeal calling for the dropping of all charges against him, citing a section of US military code that bans “unlawful pretrial punishment.”

The former army intelligence analyst had complained that he was held in isolation at Quantico, forced to strip at night and not allowed to exercise in his cell, where he spent 23 hours a day, amid fears he might commit suicide.

According to the defense's appeal, examined during Tuesday's session, Manning was constantly watched and subjected to cruel prison conditions acknowledged by military officials.

He was placed on a Prevention of Injury (POI) regimen, a status “assigned to prisoners who have given an indication that they intend or are contemplating harming themselves.” He was also designated a “maximum custody” (MAX) detainee.

On multiple occasions, Manning had asked to be relieved of such restrictive conditions, considered unjustified by psychiatrists.

One of his psychiatrists, to be heard by the defense Wednesday, said that “visual checks” of Manning every 15 minutes in his cell were “more than sufficient to ensure his safety, from a psychiatric perspective” and recommended ending his POI status, which calls for checks every five minutes.

Retired Marine colonel Daniel Choike, former commander at the Quantico prison, testified that Manning was allowed a “one hour sunshine call” per day but that, for five months, he was only given 20 minutes per day.

He said Manning was not in solitary confinement, but admitted that the brig at Quantico was “not a place for long-term pre-trial confinement” as there was “no psychological support” for those in detention.

Manning was later transferred from Quantico to a prison at Fort Leavenworth in Kansas, where he was placed under less restrictive conditions.

Protesters gathered outside Fort Meade Tuesday to show their support for Manning.

“He was held in solitary confinement for nine months, conditions that the UN chief investigator on torture held inhumane and degrading,” Emma Cape, one of about 30 protesters, told AFP.

“If we were not here, the military might not be accountable for all the violations toward Bradley Manning,” said Nathan Fuller, spokesman for a Manning support network.

“The government has to be held accountable for all the violations in the case.”The protesters, braving the rain, carried signs that read “Blowing the whistle on war crimes is not a crime” and “Free Bradley Manning.”

Arrested while serving near Baghdad, Manning is scheduled to go on trial on February 4.