Washington, Oct 7 (IANS): US President Joe Biden has announced that he's pardoning all prior federal offences of simple marijuana possession.

"There are thousands of people who were previously convicted of simple possession who may be denied employment, housing, or educational opportunities as a result," Biden tweeted on Thursday.

"My pardon will remove this burden," he said, adding that he's also calling on governors to pardon simple state marijuana possession offences.

Biden added he's asking federal officials to "initiate the administrative process to review expeditiously how marijuana is scheduled under federal law".

The US has been under criticism over the push to legalise marijuana nationwide, Xinhua news agency reported.

Marijuana, which can also be called cannabis, weed, pot or dope, refers to the dried flowers, leaves, stems, and seeds of the cannabis plant, according to the US Centers for Disease Control and Prevention. Marijuana use may have a wide range of health effects on the body and brain.

Under the Controlled Substances Act enacted by the US government in the 1970s, marijuana is a Schedule I substance, meaning that it has a high potential for abuse, no currently accepted medical use in America, and a lack of accepted safety for use under medical supervision.

However, with a growing number of US states and territories allowing and regulating medical use and even recreational use of marijuana, the movement to legalise or decriminalise the drug federally has gained steam in the nation.

Advocates claim the federal government should follow the states and allow adults to decide for themselves whether to use marijuana while framing their endeavour as a way to reverse the disproportionate impact of criminalising the substance on racial minorities.

Critics say marijuana is enough of a mind-altering substance to pose a threat to society and its nationwide legalisation would likely make US' drug problem worse.

In 2019, there were an estimated 48.2 million people in the US who used marijuana, with nearly four in 10 high school students reporting using it in their lifetime.