Sting has angered anti-drug groups by adding his name to the campaign to legalize marijuana in America.
As politicians in many states, including California, consider legalising pot, celebrities have come out in support of the suggested legislation.
And Sting wants America to spend the money it uses in the war on the drug on poverty and environmental issues instead.
In a post on his blog, the former Police singer writes, "The War on Drugs has failed - but it's worse than that. It is actively harming our society. Violent crime is thriving in the shadows to which the drug trade has been consigned.
"People who genuinely need help can't get it. Neither can people who need medical marijuana to treat terrible diseases.
"We are spending billions, filling up our prisons with non-violent offenders and sacrificing our liberties."
Sting is calling on fans to support activists at the Drug Policy Alliance (DPA), who campaign for those jailed for non-violent drug offenses to be released from prison.
He adds, "For years, the Drug War has been used as a pretext to lock people in prison for exorbitant lengths of time - people whose crimes never hurt another human being, people who already lived at the margins of society, whose voices were the faintest and whose power was the least. Meanwhile, resources to fight genuine crime - violent crime - have been significantly diminished."
But his comments have upset anti-drug activists - a spokesperson for DARE, which teaches schoolchildren about the dangers of drug use, has responded, "Sting should stick to singing and not meddle in matters he doesn't understand. We do not need pop stars coming out and making irresponsible statements like that."
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