The Obama administration, stepping up its efforts to overhaul the criminal justice system, called Thursday for the early release of more low-level, nonviolent drug offenders from federal prisons.

Deputy Attorney General James M. Cole, speaking to the New York State Bar Association’s Criminal Justice Section, said the administration wants to free inmates who no longer pose a threat to public safety and whose long-term incarceration “harms our criminal justice system.” He appealed to defense lawyers to identify candidates for clemency.

“You each can play a critical role in this process by providing a qualified petitioner — one who has a clean record in prison, does not present a threat to public safety, and who is facing a life or near-life sentence that is excessive under current law — with the opportunity to get a fresh start,” Cole told the lawyers.

His remarks were part of a broader prison reform effort by the Justice Department. In August, Attorney General Eric H. Holder Jr. announced that low-level drug offenders with no connection to gangs or large-scale drug organizations would no longer be charged with offenses that called for severe mandatory sentences. President Obama later commuted the sentences of eight inmates serving a long time for crack cocaine convictions.

Each of them had served at least 15 years and had been convicted before the 2010 Fair Sentencing Act, which sought to reduce the sentencing disparity between those convicted of crack and powder cocaine crimes.

“The president’s grant of commutations for these eight individuals is only a first step,” Cole said Thursday. “There are more low-level, nonviolent drug offenders who remain in prison, and who would likely have received a substantially lower sentence if convicted of precisely the same offenses today.”

It’s unclear how many inmates could qualify for clemency, but thousands of federal inmates are serving time for crack cocaine offenses.

Civil liberties groups, including the American Civil Liberties Union, applauded Cole’s announcement.

“The Obama administration is taking an important step toward undoing the damage that extreme sentencing has done to so many in our criminal justice system,” said Laura W. Murphy, director of the ACLU’s Washington Legislative Office.

In other action Thursday on criminal justice reform, the Senate Judiciary Committee voted to advance a bill, sponsored by Sens. Mike Lee (R-Utah) and Richard J. Durbin (D-Ill.), that would reduce mandatory minimum sentences for federal drug offenders by half and allow 8,800 federal inmates imprisoned for crack cocaine crimes to return to court to seek punishments in line with the Fair Sentencing Act.

Sen. Charles E. Grassley (Iowa), the ranking Republican on the panel, called the legislation “a step backward.” In a statement, he cited a letter sent to Holder from the National Association of Assistant United States Attorneys that said “the merits of mandatory minimum sentences are abundantly clear.”

“They provide us leverage to secure cooperation from defendants. . . . They protect law-abiding citizens and help to hold crime in check,” the group said.

Julie Stewart, president of Families Against Mandatory Minimums, called the bill “bipartisan and reasonable” and said it would “save taxpayers billions of dollars by locking up fewer nonviolent drug offenders for shorter periods of time.”

Holder, testifying before the Senate Judiciary Committee on Wednesday, said federal prison costs represent one-third of the Justice Department budget. He called the enormous costs of overburdened prisons “a growing and potentially very dangerous problem.”

The cost of incarceration in the United States was $80 billion in 2010. The U.S. population has grown by about a third since 1980, but the federal prison population has increased by about 800 percent and federal prisons are operating at nearly 40 percent over capacity, Justice officials said.