In his opening statement at the court-martial at Fort Meade, Maryland, on Monday, Private First Class Bradley Manning confirmed that he was pleading guilty to 10 charges against him but not the most serious, that of aiding the enemy.

The now 25-year-old Manning had previously admitted to passing on more than 700,000 intelligence documents to the whistle-blower website WikiLeaks.

The lead prosecutor in the trial, US Army Captain Joe Morrow, used his opening statement to portray Manning as someone who would deliberately betray his country.

"This is a case of what happens when arrogance meets access to sensitive information," Captain Morrow said, adding that the private had "systematically harvested" thousands of documents from classified databases.

"The evidence will show ... the accused knowingly gave intelligence to the enemy. He knew Al-Qaeda used WikiLeaks."

Earlier, the defense lawyer representing Manning at the trial, David Coombs, painted a very different picture of his client, describing him as "young, naïve, but good intentioned" and saying that he was someone who placed people first.

Coombs also said his client was troubled by what he saw while serving in Iraq, and he had been left traumatized after witnessing a roadside bombing involving a civilian car in late 2009.

The case, which has received international attention, is expected to run until at least late August. If found guilty of all of the 22 charges against him, Manning could face life in prison.

Manning is not the only person in hot water over the case. US federal authorities are looking into whether they can prosecute Wikileaks founder Julian Assange for publishing the leaks on his website.

Assange, though, also has more immediate legal concerns. He has been hiding in the Equadorean Embassy in London as he seeks to avoid extradition to Sweden where he is wanted for questioning about allegations of rape and sexual assault.

pfd/jr (AFP, Reuters, dpa, AP)