WASHINGTON (CNN) -- The United States, Colombia and Mexico are slowing the flow of cocaine and methamphetamine into the U.S., according to new figures from the Drug Enforcement Administration.
U.S. consumers of the illicit drugs paid more for them in 2007 than before, and the drugs are not as pure as in the past -- suggesting suppliers are diluting them to stretch limited supplies, the agency said in a statement.
Americans who bought methamphetamine paid an average of 73 percent more in September than they paid at the first of the year, but the purity of the drug decreased 31 percent, according to the DEA.
Meanwhile, the average price of a gram of cocaine jumped 44 percent in the first nine months of the year, while its purity dropped 15 percent, the DEA said.
"Drug kingpins are having a harder time moving illegal drugs and chemicals and pocketing the illicit proceeds, because they are up against the full-court press" of cooperation between the United States and its international partners, DEA administrator Karen Tandy said in the statement.
Colombia's drug eradication and interdiction programs and its commitment to extradite traffickers charged with crimes outside of Colombia have also played a role, the agency said.
U.S. state and local law enforcement and the Mexican government all have helped reduce the flow of methamphetamine, said John Walters, the Director of National Drug Control Policy. "The intense pressure placed on meth producers and traffickers has significantly disrupted the market for this devastating drug," he said, although use of the drug remains problematic.
Thirty-seven U.S. cities, including New York and Los Angeles and smaller ones such as Buffalo, New York; and Toledo, Ohio, appear to be experiencing a shortage of cocaine, the DEA said.
The U.S. has slowed the flow of coke and meth from Mexico