US President Joe Biden's administration is set to reclassify marijuana as a less dangerous drug, an official said yesterday - a historic shift that would bring federal policy more in line with public opinion.

The US Attorney General sent a proposal to the White House to "reclassify marijuana," Justice Department spokesperson Xochitl Hinojosa said in a statement.

It comes after Mr Biden became the first president to initiate a federal review into the matter, in 2022.

The issue is seen as a potential vote winner for Mr Biden as he faces Republican Donald Trump in a tough election rematch this November, especially among younger people whom the Democratic incumbent is struggling to court.

Marijuana has been classified since 1970 as a so-called "Schedule I" drug along with heroin, ecstasy and LSD, meaning it is deemed to have no accepted medical use and a high potential for abuse.

However, it would be downgraded to a Schedule III drug under the proposal, along with drugs like ketamine and painkillers containing codeine, with a moderate to low likelihood of dependence, Ms Hinojosa's statement said.

"This is the next step in the formal rescheduling process," a source familiar with the issue told AFP. The process would still require a long period for public comments and finalisation.

Commenting on the impending move, Paul Armentano, deputy director of the advocacy group NORML, said: "It is significant for these federal agencies, to acknowledge publicly for the first time what many patients and advocates have known for decades: that cannabis is a safe and effective therapeutic agent for tens of millions of Americans."

However, he added that reclassifying the substance did not go far enough and it should be removed from the Controlled Substances Act altogether, a move that would require legislation.

A Pew Research Centre survey last month found 88% of Americans said marijuana should be legal for medical or recreational use. Just 11% said it should not be legal at all.