Former President Bill Clinton expressed his alarm to U.S. mayors on Saturday about the growing opioid crisis and warned that the drug epidemic is not going to be constrained to rural America because of heroin flowing in from Mexico and fentanyl growing more attractive to inner city gangs.

“In the beginning, this despicable epidemic had a less violent delivery system. Our kids were delivered and a lot of our adults were delivered into a paralyzing addiction by doctors, pharmacists and drug manufacturers, not by armed gangs. However, this movie is coming to a theater near you,” Clinton said to the U.S. Mayors Conference in Miami. “Because as the government got better at dealing with opioids, more people moved into heroin.”

“Heroin is even cheaper now because it is now being grown in Mexico in the hidden parts of the Sierra Madre Mountains and being harvested by preteens. And then it got even cheaper with fentanyl which is a synthetic drug that if you have a 13-year-old child or certainly a 15-year-old child who can make a ‘C’ in high school chemistry and access to a garage they can learn how to make. And now it’s becoming attractive to urban gangs,” Clinton warned. “It’s going to eat us all alive.”

Clinton has been privately sounding the alarm about the effects of Mexican heroin for years, speech transcripts released by WikiLeaks last fall revealed.

“Now, what has happened is this addiction has become more expensive and more hazardous because the government’s finally doing a better job of dealing with it. So it is morphing into a heroin epidemic in all kinds of small towns and rural areas all across America,” Clinton said at a fundraiser in November 2015. “Why is that? Because in distressed areas of Mexico, they’re able to grow poppies and harvest them with preteens protected by gangs in their physical isolation, so they can ship that heroin up here much cheaper than we could otherwise get it.”

At another fundraiser that same month, Clinton said that skyrocketing addiction rates are due to the fact that “heroin poppies, or opium, is now being grown – or poppies are now being grown in the Sierra Madre mountains of Mexico, and harvested by preteens. Eight- and nine-year-old kids are paid by the drug dealers to take care of the plants, squeeze them out, and begin the process of producing heroin. That’s why heroin is so much cheaper now than cocaine.”