Attorney General Jeff Sessions signaled his support Thursday for the federal government to continue to use private prisons, rescinding a memo under President Obama meant to phase out their use.

Sessions issued a new memo to replace the one issued last August by former Deputy Attorney General Sally Yates.

The previous memo told the the Bureau of Prisons to begin reducing, and ultimately end its use of privately run prisons.

Yates said at the time the facilities were less well run than those managed by the Bureau of Prisons, and were less necessary given declines in the overall prison population.

In his memo Thursday, Sessions said that Yates' directive contradicted longstanding Justice Department policy and "impaired the Bureau's ability to meet the future needs of the federal correctional system."

The Bureau of Prisons has 12 private prison contracts, which house approximately 21,000 inmates.

The latest memo — issued just two weeks after Sessions was sworn in as attorney general — could be part of a more expansive rollback of criminal justice policies enacted by the Obama administration Justice Department, including directives against seeking mandatory minimum punishments for nonviolent drug offenders.

The private prison industry has been a major contributor to Republican political campaigns, particularly in recent years.

As a candidate, President Donald Trump said he supported the use of private prisons, and the shares of the major companies — including Geo Group and CoreCivic Co., formerly Corrections Corporation of America — jumped after the election amid anticipation that the incoming administration would again turn to them.

"I do think we can do a lot of privatizations and private prisons. It seems to work a lot better," Trump told MSNBC in March.

The federal government started to rely on private prisons in the late 1990s because of overcrowding. Many of the federal prison inmates in private facilities are foreign nationals who are being held on immigration offenses. The Yates policy did not extend to prisons used by Immigration and Customs Enforcement, which hold tens of thousands of immigrants awaiting deportation.

Immigration and human rights advocates have long complained about conditions in privately run prisons. An inspector general audit from last August said problems at private prisons in recent years included property damage, injuries and the death of a corrections officer.

Fox News' Matt Dean and The Associated Press contributed to this report.