Marijuana reclassification requested by two US governors
Two US governors have asked the federal government to reclassify marijuana to permit the drug for medical use.
Christine Gregoire of Washington state and Lincoln Chafee of Rhode Island filed the petition in a move designed to bridge the gap between federal and states' medical marijuana laws.
US federal law deems marijuana to have no medical use and puts it in the same category as heroin.
Washington and Rhode Island are among 16 states that allow medical marijuana.
Ms Gregoire, a Democrat, and Mr Chafee, an independent who was formerly a Republican, argue that the current combination of federal drug policy and states' ability to allow medical marijuana creates too many grey areas for local governments and patients.
"People weak and sick with cancer, multiple sclerosis and other diseases and conditions suddenly feel like - or in fact become - law breakers," Gov Gregoire said in a statement.
'Crude drug delivery'
The petition asks the Drug Enforcement Agency (DEA) to reassign marijuana from a Schedule I drug to Schedule II - drugs deemed to have some medical use, but a strong potential for abuse.
Over a decade ago, the Institute of Medicine called smoking marijuana a "crude drug delivery system" that exposed patients to harmful substances.
The Federal Drug Administration (FDA) refused to approve the drug for any medical use in 2006.
But in 2009, the US Supreme Court struck down an attempt to ban marijuana for medical purposes, the same year the American Medical Association recommended a reclassification.
In addition to the 16 states and the District of Columbia that currently have medical marijuana laws, 10 states are considering similar laws.
Washington and Rhode Island's petition asks the federal government to review new scientific analysis of cannabis since 2006 and hold public hearings on the possible rule change.
Both the DEA and the FDA had no immediate comment.