WASHINGTON (AP) — Attorney General Jeff Sessions is going after legalized marijuana. Sessions is rescinding a policy that had let legalized marijuana flourish without federal intervention across the country.

That’s according to two people with direct knowledge of the decision. They were not allowed to publicly discuss it before an announcement expected Thursday and spoke on condition of anonymity.

The move will leave it to U.S. attorneys where pot is legal to decide whether to aggressively enforce federal marijuana law. The move likely will add to confusion about whether it’s OK to grow, buy or use marijuana in states where it’s legal, since long-standing federal law prohibits it.

The decision comes days after California began selling recreational marijuana.

Sessions compares marijuana to heroin and blames it for spikes in violence.