Uruguay has unveiled a plan to allow state-controlled sales of marijuana to fight a rise in drug-related crime.
Under the bill, only the government would be allowed to sell marijuana to adults registered on a database.
Defence Minister Eleuterio Fernandez Huidobro said this was part of a plan to remove profits from drug dealers and divert users from harder drugs.
He said that the recent increase in murder rates was a clear symptom of a rise in drug trafficking crimes.
"We believe that the prohibition of certain drugs is creating more problems for society than the drugs themselves... with disastrous consequences," Mr Fernandez Huidobro said, presenting the bill.
"Homicides related to settling scores have increased, and that's a clear sign that certain phenomena are appearing in Uruguay that didn't exist before," he said.
The authorities blame the rise in crime in Uruguay on hard drugs, specifically crack cocaine.
The new bill envisages that some shops would be allowed to sell marijuana cigarettes at a price fixed by the authorities.
The government also wants to create a user database to supervise consumption.
BBC regional correspondent Vladimir Hernandez says the move is seen as groundbreaking in South America.
Several Central American leaders - including the presidents of Guatemala and Costa Rica - have spoken of the need to consider decriminalising some drugs in an attempt to undermine cartels.
In Uruguay alone, the illegal marijuana market is estimated to be worth about $75m (£48m) a year.
But the new bill has already proved controversial, and the debate in Congress could take several months, our correspondent says.