Fort Meade, Md. - An attorney for Pfc. Bradley Manning on Monday asked a military judge for leniency in the sentencing of his client, as prosecutors sought to have the former Army intelligence analyst imprisoned for 60 years.

The pleas came during closing arguments in the sentencing phase of Manning's court-martial at Fort Meade, Md., following his conviction last month on 20 offenses, including six violations of the Espionage Act.

Manning faces up to 90 years in prison. His attorney, David Coombs, called on the judge to hand down "a sentence that allows him to have a life." Coombs stressed that Manning had been a young, struggling, idealistic soldier with "humanist" beliefs when he leaked hundreds of thousands of documents to the anti-secrecy website WikiLeaks in early 2010.

"He cares about human life," Coombs said. "His biggest crime was he cared about the loss of life he was seeing and was struggling with it."

Manning's defense team has argued that the Army bore responsibility for his actions because commanders had not recognized that the soldier was experiencing mental health problems shortly before he deployed to Iraq and while he was there.

A military prosecutor on Monday rejected that argument and emphasized that Manning, now 25, consciously broke the law.

"The Army didn't betray Pfc. Manning. Pfc. Manning betrayed the Army," said the prosecutor, Capt. Joe Morrow.

Manning, Morrow contended, was a "determined insider who exploited an imperfect system. Every day was another day to stick his finger in the eye of the classification system of the military."

Morrow highlighted the damage that government officials have said the leak caused, and portrayed Manning as a soldier who suffered from temper tantrums, not mental health problems. The prosecution insisted that Manning's unit had put a priority on soldiers' mental health and would not have deployed a soldier who was not equipped to be in a war theater.

It was unclear why prosecutors were seeking 60 years, given that Manning faces up to 90. Still, Coombs said he was surprised by the prosecution's plea for even 60 years.

"Manning is a lot of things," Coombs said. "He is a young man. He is a very intelligent man. He's a little geeky at times. But he is caring, compassionate. He is respectful, he was in fact naive, and certainly was good-intentioned."

The judge, Col. Denise Lind, is expected to hand down a sentence this week.

Coombs has said that he will continue working with Manning in a bid to gain clemency from the military. Additionally, the case will be sent to an appellate court immediately.

In an address to the court last week, Manning expressed regret for the leaks and the "unintended consequences" of his actions. Earlier in the trial, he had justified the leaks as necessary to spark a debate about the nation's preoccupation with "killing and capturing people."