The president announced a pardon of all prior federal offenses of simple possession of marijuana yesterday in a move that will benefit an estimated 6,500 people with federal convictions for simple possession of marijuana.

As a presidential candidate, Mr Biden promised to decriminalise cannabis use, as well as expunging convictions.

In a statement, the president said: “There are thousands of people who have prior Federal convictions for marijuana possession, who may be denied employment, housing, or educational opportunities as a result. My action will help relieve the collateral consequences arising from these convictions.”

A demonstrator waves a flag with marijuana leaves depicted on it during a protest calling for the legalization of marijuana, outside of the White House on April 2, 2016, in Washington. President Joe Biden is pardoning thousands of Americans convicted of simple possession of marijuana under federal law, as his administration takes a dramatic step toward decriminalizing the drug. (AP Photo/Jose Luis Magana, File)

He went on to urge all governors to do the same with regards to state offenses, saying, “Just as no one should be in a Federal prison solely due to the possession of marijuana, no one should be in a local jail or state prison for that reason, either.”

The president also called on the Secretary of Health and Human Services and the Attorney General to begin the administrative process to review how marijuana is scheduled under federal law.

Ukraine conflict: Joe Biden: Nuclear ‘Armageddon’ risk highest since Cuban Missi...

He added: "We classify marijuana at the same level as heroin - and more serious than fentanyl," said Mr Biden. "It makes no sense."

Marijuana is currently classified in Schedule 1 of the Controlled Substances Act under federal law. This classification puts marijuana in the same schedule as for heroin and LSD and even higher than the classification of fentanyl and methamphetamine.

Recreational marijuana is already legal in 19 states and Washington DC. Medical use is legal in 37 states and three US territories.

Biden also added he would call upon all state governors to issue their own marijuana pardons.

He is also directing the Department of Justice and the Department of Health to review how cannabis is classified under federal law.

The pardons come a month before November's congressional mid-term elections – with Biden following President Donald Trump who on the last day in office pardoned 12 marijuana offenders, including some who had been jailed for life under the three-strikes rule.

Joe Biden to pardon all federal offenses of simple marijuana possession