UNITED States President Barack Obama yesterday cautioned persons who have hopes of marijuana being legalised, as he explained the difference between legalisation and decriminalisation.

"We had some discussion with Caricom (Caribbean Community) countries about this. I know, on paper, that a lot of folks think that if we just legalise marijuana then it will reduce the money flowing into the transnational drug trade, [bringing in] more revenues and jobs created," the US president said yesterday.

He was answering a question raised by Miguel 'Steppa' Williams, one of the more than 300 youth leaders who attended yesterday's youth forum held at the University of the West Indies in St Andrew.

"I have to tell you that it's not a silver bullet because, first of all, if you are legalising marijuana, how do you deal with other drugs and how do you draw the line?" the US president asked.

He also expressed reservation about the methods that some countries continued to use in their war on drugs with a lot of emphasis being placed on incarceration.

This method, Obama said, was counter-productive, suggesting that he supported the decriminalisation of a small amount of marijuana for personal use.

He said: "The so-called war on drugs has been so heavy in emphasising incarceration that it has been counter-productive. You have young people who did not engage in violence who get very long penalties and are placed in prison and then are rendered economically unemployable or almost pushed into the underground economy and learn crime more effectively in prison." The US president said as a result of this families are devastated, saying that what needs to be done is to reform criminal justice systems.

"There are two states in the United States that have embarked on an experiment to decriminalise or legalise marijuana -- Colorado and Washington State -- and we will see how that experiment works its way through the process," Obama said.

"Right now that is not federal policy and I do not foresee, anytime soon, Congress changing the law on a national basis, but I do think that if there are states that show that they are not suddenly a magnet for additional crime, that they have a strong enough public health infrastructure to push against the potential of increased addiction, then it's conceivable that that will spur on a national debate, but that is going to be some time off," he added.

He also cautioned that if steps were taken to legalise marijuana it could lead to another issue.

"In the global economy, generally, if you have small- or medium-sized marijuana businesses scattered across the Caribbean and marijuana is suddenly legal, big multinational companies will come in and try to market and control and profit from the trade," said the US president.

"I think we have to have a conversation about this, but... we need to decrease demand and we need to focus on a public health approach to decreasing demand and to stop the flow of guns and cash into the Caribbean and Central America and Latin America," Obama said. "I think the Caribbean, Latin America and Central America have to cooperate with us [as we] try to shrink the power of the transnational drug organisations that are vicious and hugely disruptive," added Obama.

Jamaica's Parliament recently approved amendments to the Dangerous Drugs Act which will allow persons with small amounts of marijuana for personal use to pay a fine.