The U.S. Drug Enforcement Administration will deny requests that it change the legal classification of marijuana and reject arguments that marijuana has medical value, according to multiple news reports late Wednesday.

The denial, which could be announced as early as Thursday, means marijuana will remain a Schedule I controlled substance and subject to the tightest restrictions, even though four states have now legalized cannabis for recreational use and 25 states plus the District of Columbia have medical marijuana laws. The federal government considers Schedule I substances to have no accepted medical use.

DEA spokesman Russell Baer confirmed to The Denver Post that a “marijuana-related” announcement would come Thursday morning, but did not disclose specifics.

The DEA for months had been considering a petition to reschedule marijuana, a move that could have opened the door to more research on the drug and eased the path to cannabis-based medicines. Part of that analysis included studying a previously unpublished recommendation by the Food and Drug Administration over marijuana’s medical uses.

Sources told The Washington Post on Wednesday that the FDA concluded marijuana has no accepted medical value, dooming the rescheduling petition.

“This decision isn’t based on danger,” DEA Administrator Chuck Rosenberg told National Public Radio. “This decision is based on whether marijuana, as determined by the FDA, is a safe and effective medicine, and it’s not.”

The decision angered marijuana supporters.

“DEA’s decision flies in the face of objective science and overwhelming public opinion,” National Cannabis Industry Association executive director Aaron Smith said in a statement late Wednesday.

The DEA will, however, ease one restriction on marijuana, The New York Times reported Wednesday.

The DEA plans to increase the supply of marijuana federally approved for research by allowing other universities to apply to grow cannabis, The Times reported, citing unnamed sources. Currently, only the University of Mississippi has the authority to grow marijuana for research purposes. As of April 4, 2016, it had 185 batches of marijuana, according to a DEA letter to members of Congress.

Some researchers and lawmakers have bristled at the “NIDA monopoly.”

In recent weeks, researcher Dr. Sue Sisley, who is leading the first placebo-controlled trial that uses raw marijuana for post-traumatic stress disorder research, said her team had yet to receive the study plant for the trial. NIDA also failed to achieve the phenotype and potency requested, she said.

U.S. Rep. Earl Blumenauer, D-Ore., who has backed marijuana-related efforts, including allowing Veterans Affairs doctors to discuss cannabis with patients, lauded the potential to remove “the National Institute on Drug Abuse monopoly.”

“It’s outrageous that federal policy has blocked science for so long,” Blumenauer said in a statement. “However, this decision doesn’t go far enough and is further evidence that the DEA doesn’t get it. Keeping marijuana at Schedule I continues an outdated, failed approach — leaving patients and marijuana businesses trapped between state and federal laws.”

Last week, Baer told The Denver Post that the DEA was in the “final stages” of determining how to classify marijuana under the Controlled Substances Act. Currently, marijuana is listed among Schedule I drugs — alongside heroin, LSD and ecstasy — which are defined by the act as the “most dangerous,” have high potential for abuse and no medical use.

Under the federal classification scheme for controlled substances, as the schedule progresses downward through schedules I, II, III, IV and V, the abuse potential, as well as the risk for psychological and physical dependence, decrease.

Industry experts have speculated that marijuana could be classified under Schedule II, joining the likes of cocaine, methamphetamine, oxycodone, fentanyl, Adderall, Vicodin and Ritalin.

Such a classification could lift some barriers to research, lead to cannabis medicines that physicians prescribe, allow the industry to import and export across state lines, ease restrictions on banking and give protections to workers, analysts have said.

Earlier Wednesday, the National Conference of State Legislators filed a resolution imploring Congress and federal regulators to remove marijuana from Schedule I classification so that legal cannabis businesses could openly bank.

“Without banking options, cannabis-related businesses are forced to operate exclusively in cash; and a large and growing cash-only industry attracts criminal activity and creates substantial public safety risks,” according to the resolution. “A cash-only industry reduces transparency in accounting and makes it difficult for the state to implement an effective regulatory regime that ensures compliance.”

Late last year, several members of Congress sent a letter to the DEA, the Department of Health and Human Services and the Office of National Drug Control Policy inquiring about medical marijuana research and the potential for rescheduling, according to The Washington Post. In the DEA’s April response, officials said the agency “hopes to release its determination in the first half of 2016.”