HARRISBURG, Pa. (AP) -- Pennsylvania needs to decriminalize small amounts of marijuana possession, Democratic Gov. Tom Wolf said Monday, yet he remains guarded about the kind of recreational legalization that is in place in several western states.

Pennsylvania Gov. Tom Wolf

While some cities have stopped arresting people for possessing small amounts and prosecutors have been downgrading it as a crime, the state should act because too many people are still going to prison for marijuana possession, Wolf said.

"I think we need to do that in a more systematic fashion," Wolf told WITF-FM's Smart Talk program. "There are too many people who are going to prison because of the use of very modest amounts or carry modest amounts of marijuana, and that is clogging up our prisons, it's destroying families and it's hurting our economy, so I think decriminalization is the first step."

According to the marijuana advocacy group NORML, 20 states and Washington, D.C., have decriminalized certain marijuana possession offenses, making it either a summary offense, like a minor traffic violation, or a misdemeanor that carries no threat of jail time.

The Pennsylvania District Attorneys Association is not opposed to downgrading the penalty for possession of small amounts of marijuana from the misdemeanor that it currently is, but very few people go to jail for it, said Ed Marsico, the Dauphin County district attorney.

"That's far from clogging up our jails," Marsico said. "There are plenty of people in jail with drug problems, and we realized years ago that treatment is the best way to work with those offenders, but basically nobody goes to jail for possession of a joint."

Thirty days in jail is the maximum penalty for misdemeanor possession. Prosecutors are working to keep any sort of drug possession cases from going to jail, Marsico said, although drug dealers are another matter.

Wolf stopped short of endorsing the kind of full legalization of recreational use that has taken place for adults 21 and over in Colorado, Washington, Oregon and Alaska.

"I'm not sure why we need to go beyond (decriminalization), and I think we can watch what happens in Colorado and Washington and Oregon and see what their experience is," Wolf said. "I'm not sure it's been uniformly great."

The Republican-controlled Legislature has made no move to consider decriminalization of marijuana.

Bills that would decriminalize certain marijuana possession offenses for adults have seen no movement, and the Legislature did not include a decriminalization provision when it approved a medical marijuana program in Pennsylvania.

Wolf signed the medical marijuana bill in April. The Department of Health said it will take until early 2018 to make medical marijuana available to eligible patients.