Amazon is backing a US bill that would legalize marijuana nationwide and will drop a requirement that recruits undergo testing for the drug, the e-commerce giant said.

A growing number of US states have moved to legalize the drug, although it remains prohibited at the federal level.

"We hope other employers will join us and that politicians move quickly to pass this law," Dave Clark, head of global operations, said in a blog post Tuesday.

"In the past, like many employers, we have disqualified people from positions at Amazon if they tested positive for marijuana use," he added.

Workers at Amazon will only be made to undergo testing for marijuana use in the event of an incident
Workers at Amazon will only be made to undergo testing for marijuana use in the event of an incident AFP / David Becker

"But given the evolution of laws in different states of the country, we will no longer include marijuana in our extensive drug testing programs."

Instead, as with alcohol, workers will only be made to undergo testing in the event of an incident.

Civil groups and elected officials have said that bans on cannabis disproportionately affect Black and Latino communities.

New York's state governor signed a law in March allowing for recreational marijuana, joining 14 other American states in the move to legalization.