The President's acting Attorney General, Todd Blanche, signed an order reclassifying state-licensed medical marijuana on Thursday. 

He said the effort was 'delivering on President Trump's promise' to expand medical options for Americans. 

'This rescheduling action allows for research on the safety and efficacy of this substance, ultimately providing patients with better care and doctors with more reliable information,' Blanche's statement said. 

The shift marks a significant step toward loosening federal barriers on marijuana.

The order establishes a system for marijuana producers to register with the Drug Enforcement Administration (DEA) and helps legitimize the 40 medical cannabis programs within the states that have passed laws adopting the shops. 

Trump ordered the review in December, targeting cannabis's Schedule I designation - a category reserved for drugs like heroin, LSD and ecstasy. The reclassification is expected to ease limits on research and expand legal use.

'The Administration continues to expeditiously implement President Trump's December executive order to increase medical marijuana research to close the gap between current medical marijuana use and medical knowledge,' a White House official told the Daily Mail on Wednesday.

The official said 'specifics related to possible reclassification' would come from the Department of Justice. The DOJ did not respond to the Daily Mail's request for comment. 

The Drug Enforcement Administration is planning to announce an administrative hearing on the rescheduling, two people familiar with the matter told the Washington Post. 

The administration's plan would move to classify cannabis as a Schedule III substance, which is the same category as prescription painkillers, ketamine and anabolic steroids. 

However, rescheduling cannabis is broadly unpopular among congressional Republicans.