The Justice Department announced on Thursday that it had loosened legal restrictions for medical marijuana, which officials said would allow for more research and treatment options.

The move does not affect the broader criminal classification of recreational marijuana as a Schedule I drug under the Controlled Substances Act. But the acting attorney general, Todd Blanche, said the Drug Enforcement Administration would hold a hearing in June to consider doing so.

The new rule moves F.D.A.-approved marijuana and state-regulated marijuana out of the Schedule I category, which includes drugs like heroin that have the strictest restrictions, and into Schedule III, a group of drugs that includes ketamine and carries fewer restrictions.

Marijuana advocates have long argued that federal drug laws are too restrictive with cannabis, an argument that has gained traction among federal and state officials. The Biden administration began the regulatory process to loosen restrictions on marijuana, but that effort was hampered by delays inside the D.E.A.

Last December, President Trump signed an executive order instructing the Justice Department to redouble efforts to change the classification of marijuana, removing it from the list of addictive drugs with no medical purpose, like heroin, and placing it instead among less addictive drugs that have medical uses.

The Justice Department action comes days after Mr. Trump publicly complained that officials had not enacted his order.

At an Oval Office ceremony last weekend with the podcaster Joe Rogan, Mr. Trump told other officials, “Will you get the rescheduling done?” He then turned to Mr. Rogan and said, “Joe, they’re slow-walking me on rescheduling.”

The ceremony was held to honor the signing of another executive order about drugs, one that directed more research into the therapeutic benefits of mind-altering drugs like Ecstasy, LSD and psilocybin.