Washington: US President Barack Obama commuted the sentences of 58 more federal prisoners, seeking to add momentum to his drive to allow earlier releases of men and women serving lengthy terms for drug offences. The newly announced commutations on Thursday brought the total number of commutations to 306 which Obama issued since taking office over seven years ago, Politico reported. More than two years ago, the Obama administration launched a "Clemency Initiative" that prompted more than 36,000 prisoners to request assistance filing applications for commutations. Obama aides hoped thousands of prisoners would have their sentences shortened through the initiative. However, the president's effort encountered bureaucratic obstacles and has been dependent to a large degree on volunteer lawyers organised through an outside consortium called Clemency Project 2014. In January, the Justice Department's pardon attorney quit, citing a lack of resources and an inability to communicate directly with the White House. White House counsel Neil Eggleston recently vowed to speed up the clemency drive. Meanwhile, top Justice Department officials have been urging lawyers for the inmates to get applications soon so that they can be presented to Obama before he leaves office. "I’ve been working to bring about a more effective approach to our criminal justice system, particularly when it comes to drug crimes. Part of that effort has been to reinvigorate our commutations process," Obama said on Thursday. "While I will continue to review clemency applications, only Congress can bring about the lasting changes we need to federal sentencing. That is why I am encouraged by the bipartisan efforts in Congress to reform federal sentencing laws, particularly on overly harsh mandatory minimum sentences for non-violent drug offences."