Trump signs order to reclassify marijuana as less dangerous drug amid GOP backlash

Marijuana previously was labeled a Schedule 1 drug under the Drug Enforcement Administration (DEA) regulations - the same category the agency uses for drugs including heroin, ecstasy and LSD. The agency claims on its website that these drugs are considered to have "no currently accepted medical use and a high potential for abuse" with no accepted medical use. 

"This reclassification order will make it far easier to conduct marijuana-related medical research, allowing us to study benefits, potential dangers, and future treatments," Trump said in the Oval Office on Thursday. "It's going to have a tremendously positive impact." 

Trump signaled he would sign the executive order Monday, when he told reporters that he was eyeing a reclassification of the drug. 

Specifically, the lawmakers claimed that reclassifying marijuana would send the wrong message to America's youth, and cautioned it would jeopardize road safety.

"We write to urge you to oppose rescheduling marijuana, a harmful drug that is worsening our nation's addiction crisis," the lawmakers wrote in the letter. "Reclassifying marijuana as a Schedule III drug will send the wrong message to America's children, enable drug cartels, and make our roads more dangerous."

Fox News' Elizabeth Elkind contributed to this report.