Former U.S. Attorney General Eric Holder said he believes marijuana should no longer be a Schedule I substance — the classification for the most dangerous drugs that have no medical use — and should instead be put in a lower category. The comments came in a new PBS “Frontline” interview published this week, in which he discussed the country’s approach to drugs and his hopes for criminal justice reform.

“I certainly think it ought to be rescheduled,” Holder said, referring to marijuana’s classification. “You know, we treat marijuana in the same way that we treat heroin now, and that clearly is not appropriate. So at a minimum, I think Congress needs to do that. Then I think we need to look at what happens in Colorado and what happens in Washington.”

Colorado and Washington have both legalized recreational marijuana use in the past few years, and now Alaska, Oregon and Washington, D.C., have done so as well. A number of states have passed legislation allowing medical marijuana, and some have decriminalized the possession of a small amount of marijuana.

PBS “Frontline” conducted the interview with Holder last year but released it this week with its documentary on the country’s heroin crisis. Holder’s statement on rescheduling marijuana went further than comments he had made in the past. In September 2014, when he was still attorney general, he said reclassifying the drug was “something that I think we need to ask ourselves and use science as the basis for making that determination,” ThinkProgress reported.

In a 2014 congressional hearing, Holder also said he would be “more than glad to work with Congress” to reclassify weed, while President Barack Obama has also said progress on marijuana reform would need to come from Congress. Holder’s replacement, Attorney General Loretta Lynch, has not talked much about the subject, but said during her confirmation hearing in January 2015 that she did not support marijuana legalization.

“I can tell you that not only do I not support legalization of marijuana, it is not the position of the Department of Justice currently to support the legalization, nor would it be the position should I become confirmed as attorney general,” she said, the Guardian reported at the time.

In the “Frontline” interview, Holder said the United States needs to deal with drugs and addiction as a public health problem and added that he believes it is time for Congress to consider decriminalizing marijuana.

“I think that certainly that ought to be a part of the conversation,” he said. “You know, where do we want to be as a nation? Now, there’s certain drugs I just can’t see. It’s hard for me to imagine ever decriminalizing crack cocaine, drugs like that. But the whole question of should marijuana be decriminalized, I mean, that’s a conversation I think that we should engage in.”