"The United States is home to five percent of the world's population, but 25 percent of the world's prisoners," Obama said in his weekly radio address. "Every year, we spend $80 billion to keep people locked up."
The president said the reason the United States has such a high prison population -- 2.2 million -- is that more non-violent offenders have been put behind bars over the past decades than ever before, AFP reported.
Despite efforts to address the matter, "much of our criminal justice system remains unfair," Obama said. "In recent years, more of our eyes have been opened to this truth. We can't close them anymore."
Among other things, "justice means that the punishment should fit the crime," Obama said.
While the US population has increased by 30 percent since 1980, the country's prison population jumped 800 percent during the same period.
The result is a record rate of incarceration for an industrialized country, which has overburdened the federal prison system.