A Department of Justice review of the nation's clemency system that could free thousands of prisoners was motivated by President Obama's desire "to make sure that everyone has a fair shot," the White House said Monday.

"He has asked the Department of Justice to set up a process aimed at ensuring that anyone who has a good case for commutation has their application seen and evaluated thoroughly," press secretary Jay Carney said Monday.

Earlier in the day, Attorney General Eric Holder posted a message to the Justice Department's website saying that new guidelines would be posted this week on which type of federal offenders would become eligible for clemency.

"Once these reforms go into effect, we expect to receive thousands of additional applications for clemency,'' Holder said.

That review is expected to place a special emphasis on non-violent drug offenders, and especially those given longer sentences for crack cocaine. In recent years, federal lawmakers have moved to reduce additional penalties for those in possession of crack, rather than powder, cocaine, in a bid to both reduce prison populations and the unequal prosecution of minorities. 

"As a society, we pay much too high a price whenever our system fails to deliver the just outcomes necessary to deter and punish crime, to keep us safe, and to ensure that those who have paid their debts have a chance to become productive citizens,'' Holder added.

At the White House, Carney wouldn't say how many people he expected to be granted clemency under the review.

"In terms of how many deserving candidates are out there, I couldn't begin to speculate," Carney said.

He suggested Obama would prefer that those "serving unfairly long sentences under outdated guidelines" be freed through congressional action, rather than presidential decree.

"The clemency process is not an appropriate vehicle to address that injustice in a comprehensive way," Carney said. "That should be done through bipartisan legislation like the measures currently working their way through Congress. And as you know, this is an issue on which there is a bipartisan coalition that believes actions needs to be taken, and there are measures in Congress that reflect that."

Last week, White House counsel Kathryn Ruemmler said the effort "reflects the reality that our overburdened federal prison population includes many low-level, nonviolent offenders without significant criminal histories."

Obama has commuted the sentences of only 10 individuals so far through his presidency, the majority of whom were convicted on federal crack cocaine charges.