EL RENO, Okla. — Peering from the back seat of his armored black limousine, President BarackObama rode into a razor wire-surrounded federal prison Thursday and said he met young inmates “who made mistakes that aren’t that different than the mistakes I made.”

Obama came to the medium-security El Reno Federal Correctional Institution near Oklahoma City to press his case that the nation needs to reconsider the way crime is controlled and prisoners are rehabilitated. The president met with inmates and walked past rows of empty cells secured by large grey doors. Prison officials opened cell no. 123 for Obama and he gazed at its sparse trappings: a double bunk bed and third bed along the wall, a toilet and sink, along with a small bookcase and three lockers.

“Three full-grown men in a 9-by-10 cell,” he said.

The White House said Obama was the first sitting president to visit a federal prison.

The president said there must be a distinction between young people “doing stupid things” and violent criminals. Young people who make mistakes, he said, could be thriving if they had access to resources and support structures “that would allow them to survive those mistakes.”

“When they describe their youth and their childhood, these are young people who made mistakes that aren’t that different than the mistakes I made,” Obama said.

Among the changes Obama is seeking is the reduction or outright elimination of severe mandatory minimum sentences for non-violent offenders. Earlier this week, he used his presidential powers to shorten the prison sentences of 46 people convicted on charges involving drugs.

The president has also called for restoring voting rights to felons who have served their sentences, and said employers should “ban the box” that asks job applicants about their criminal histories.