Central America continues to be the major transit zone for illegal drugs making their way from the highlands of South America into the United States, according to a new study from the U.S. State Department.

Surpassing the more traditional Caribbean and Pacific routes used by drug traffickers in the past, around 90 percent of all illegal drugs that make their way into the American market through the Central America/Mexico corridor, concluded the State Department's 2014 International Narcotics Control Strategy Report, unveiled in March.

“This has been this way since around 2006,” Adam Isacson, a senior analyst Washington Office on Latin America, a think tank, told Fox News Latino. “That was when anti-drug efforts really shut down parts of the eastern Pacific and regions of the Caribbean.”

While not as well publicized as its anti-drug efforts in Mexico and Colombia – the Merida Initiative and Plan Colombia, respectively – the U.S. sends $85 million annually to the region and provides technical assistance to Central America in an effort to curb this drug flow.

The U.S. government has touted a number of high profile arrests and seizures, but it hasn’t stopped drug trafficking organizations from Mexico and Central America from setting up shop in major U.S. cities like Atlanta, Chicago and Washington D.C.

“These criminal gangs have significant drug trafficking and other criminal links in major U.S. cities,” according to the State Department report. “Anti-gang units in Central America led to a homicide arrest in Oklahoma City, the prosecution of felony extortions in Annapolis and the capture of one of the FBI’s top ten most wanted fugitives, a suspect who was arrested in El Salvador.”

Police in El Salvador reported late last year that the country’s notorious street gangs – among them MS-13 and Barrio 18 – were becoming more deeply involved in drug trafficking.

El Salvador's anti-narcotics division reported capturing 1,036 gang members in 2013 for drug related crimes, nearly twice the 2012 number of 590. They also said they "dismantled" 29 drug trafficking structures.

"Soon it will not seem strange to us that they are fully dedicated to drug trafficking," said Hector Mendoza Cordero, deputy director of the National Police, according to the Salvadoran newspaper La Prensa Gráfica.

U.S. drug enforcement agents and military officials have both recently claimed that there has been a significant rise in drug trafficking in the Caribbean.

“What we’re seeing is that traffickers are increasing the amount of cocaine in each shipment,”said Vito S. Guarino, special agent in charge of the Drug Enforcement Administration’s Caribbean division, based in Puerto Rico, according to the Miami Herald. “This is a shift toward the Caribbean. . . . And the picture we’re looking at right now will be the picture for the next few years.”

However, the State Department report seems to contradict the claims that drug trafficking is rampant through the Caribbean, citing that cocaine coming through the Caribbean rose from five to nine percent between 2011 and 2012.

“There has been a lot of talk about a major rise in drug trafficking in the Caribbean,” Isacson said. “And while this may still happen, it’s not what’s going on now.”

Follow Andrew O'Reilly on Twitter @aoreilly84.

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