President Barack Obama pauses as he speaks at the El Reno Federal Correctional Institution in El Reno, Okla. during a visit in July 2015. (Evan Vucci/AP)

President Obama granted commutations Tuesday to 79 federal drug offenders who were imprisoned under harsh and outdated sentencing laws, pushing to more than 1,000 the number of inmates who have received clemency from him.

Obama’s historic number of commutations — more than the previous 11 presidents combined — was announced as administration officials are moving quickly to rule on all the pending clemency applications before the end of the president’s term. The Trump administration is not expected to keep in place Obama’s initiative to provide relief to nonviolent drug offenders.

About a third of the 1,023 inmates who have been granted clemency, 342 prisoners, were serving life sentences for their ­offenses.

“The President’s gracious act of mercy today with his latest round of commutations is encouraging,” said Brittany Byrd, a Texas attorney who has represented several inmates who have received clemency since Obama’s initiative began in 2014.

“He is taking historic steps under his groundbreaking clemency initiative to show the power of mercy and belief in redemption. Three hundred and forty-two men and women were set to die in prison. The president literally saved their lives.”

Eighteen of the inmates granted clemency Tuesday were serving life sentences.

The White House and the Justice Department were criticized this year by advocates of sentencing policy changes who said the administration was moving too slowly in granting commutations to inmates serving harsh sentences who met the clemency criteria. The administration has greatly picked up the pace, with 839 commutations granted by Obama this year alone. But advocates want officials to move faster before time runs out.

“At the risk of sounding ungrateful, we say, ‘Thanks, but please hurry,’ ” said Kevin Ring, vice president of Families Against Mandatory Minimums. “We know there are thousands more who received outdated and excessive mandatory sentences and we think they all deserve to have their petitions considered before the president leaves office. Petitioners are starting to get anxious because they know the president is, in prison parlance, a ­short-timer.”

During his campaign, President-elect Donald Trump called for a tougher stance on crime and sharply criticized Obama’s initiative to grant clemency to nonviolent drug offenders.

“Some of these people are bad dudes,” Trump said. “And these are people who are out, they’re walking the streets. Sleep tight, folks.”

In a conference call with reporters, Deputy Attorney General Sally Yates said that the Justice Department will continue to recommend more commutations through the end of the Obama administration. Yates said she and the U.S. pardon attorney are committed to reviewing and making recommendations for the approximately 6,000 clemency petitions from drug offenders that were pending as of Aug. 31.

White House Counsel W. Neil Eggleston said that Obama had demonstrated that “our nation is a nation of second chances and mistakes from the past will not deprive deserving individuals of the opportunity to rejoin society and contribute to their families and to their communities.”

Not all of the inmates who have been granted clemency, however, will be released immediately or even in a number of months. Beginning this past summer, the Obama administration began granting clemency to some inmates by reducing their sentences; in some cases they will remain in prison for years, as first reported by USA Today.

Eggleston said that Obama reviews each clemency case on an individual basis, considering the sentence that would have been imposed today and the prisoner’s likelihood of success upon his or her release.

“So, what we’ve seen is . . . generally the people who are serving longer are serving the amount of time they would be sentenced to if they were sentenced today,” Eggleston said. “That may be a period of two years, three years, five years, [or] some additional period, whatever that might be.”

Of the 1,023 commutations, 523 were from inmates who were helped by Clemency Project 2014, a group of about 4,000 volunteer lawyers from across the country who signed up over the past two years in what has become one of the largest-ever pro bono legal efforts.

Yates described Tuesday’s milestone as “more than just a ­statistic.”

“There are 1,000 lives behind that number,” said Yates, who makes the final decision in the Justice Department about whether to recommend clemency to Obama. “One thousand people who have been sentenced under unnecessarily harsh and outdated sentencing laws that sent many of them to prison for 20, 40 years, sometimes even life, for nonviolent drug offenses.”

Norman Brown is one of those 1,000 inmates.

“The day I received clemency was so overwhelming that I had to pinch myself to see if what I heard was real,” said Brown, who lives in Hyattsville, Md. and was sentenced in 1993 to life in prison for possession and distribution of crack and for aiding and abetting. “I sat on the phone with my attorney and I was speechless for about three minutes.”

Brown was one of several inmates chosen to have lunch with Obama in March. He works with two organizations, helping both juveniles and adults in prison and those who have received clemency to make the transition back to their communities.

Shauna Barry-Scott, of Youngstown, Ohio, who was sentenced to 20 years in 2005 for selling crack, described the clemency grant from Obama as a “surreal feeling . . . shock, overwhelming joy, fear of the unknown and a bit of sadness, too, for the others left behind.”

“A million thoughts ran through my mind,” Barry-Scott said, “wondering what the world was going to be like after being away for so many years, most of all realizing I would finally be reunited with my children after all this time.”