Francis, who has spoken out against drug use several times, said that to ensure young people did not fall prey to drugs, society had to say "'yes' to life, 'yes' to love, 'yes' to others, 'yes' to education, 'yes' to greater job opportunities".
"If we say 'yes' to all these things, there will be no room for illicit drugs, for alcohol abuse, for other forms of addiction," he said in remarks to a drug enforcement conference in Rome carried on the website of Vatican radio.
"The scourge of drug use continues to spread inexorably, fed by a deplorable commerce which transcends national and continental borders," he said.
Pressure on Western governments to ease restrictions on so-called "soft drugs" such as marijuana has led to a number of countries legalizing their use under certain circumstances.
The state of New York prepared on Friday to pass measures that should lead to it becoming the 23rd U.S. state to allow medical use of marijuana.
This week, Uruguay, which has already legalized the production and sale of cannabis, said it would also allow doctors to prescribe the drug to treat certain conditions.
"Attempts, however limited, to legalize so-called 'recreational drugs', are not only highly questionable from a legislative standpoint, but they fail to produce the desired effects," the pope said.