Attorney General Eric Holder issued a blunt warning today to Mexican drug cartels that he said pose a national security threat: "These cartels will be destroyed."
The warning came as the attorney general and acting Drug Enforcement Administration chief Michele Leonhart announced the completion of the final phase of DEA's "Operation Xcellerator," which targeted the Sinaloa cartel, a major western Mexico drug operation that has been expanding its reach into the United States.
The officials said that as a result of the operation, more than 750 suspected Mexican drug cartel members had been arrested and more than 23 tons of narcotics had been seized during the past 21 months.
The Sinaloa cartel is one of several believed to responsible for kidnappings and murders within the United States in addition to extraordinary carnage in Mexico.
As part of the operation, authorities made arrests in Chicago, Minneapolis, Boise, Atlanta, San Diego, Los Angeles, San Francisco, Houston, San Antonio and Miami.
But it's not just major metropolitan areas that have been blighted by the cartel's aggression.
In northeastern Ohio, the suburban community of Stow "became a conduit for criminals running cocaine," Leonhart said, citing an example of how large-scale cartel operations trickle down to smaller communities far removed from the U.S.-Mexico border.
"Just underneath the surface of this peaceful city, the Sinaloa cartel had been sending cocaine through this community's local airport, ferrying dozens of kilos of cocaine from California to Stow on a regular basis," she said.
The profits from the sales of illicit drugs allow the cartels to expand "violent enterprises further into our heartland," Leonhart said.
"So consider that the cartels that are making life unbearable in border towns in Mexico are contributing to trafficker violence in the United States," she said.
"International drug trafficking organizations pose a sustained, serious threat to international safety and security. They are a national security threat," Holder said in his first major crime press conference since his confirmation.
Cartels: 'Organized Crime, Married to Savvy Business Practices'
The groups "bear the hallmarks of organized crime, married to savvy business practices that allow for successful international commerce," he said, and operate "with stunning planning and precision."
The case shows how mammoth the Mexican cartels have become, and how far their reach is within the United States -- in some cases surpassing the influence of the notorious Colombian cartels.
"It is no secret that we are now seeing many more international aspects to cases that were once only domestic ones," Holder said. "As our world grows smaller, the ability of criminals from outside the United States to operate within our borders grows larger."
Officials estimate that the street value of drugs seized in the investigation tops $1 billion, and includes more than 12,500 kilograms of cocaine, 16,000 pounds of marijuana and other drugs including methamphetamine, heroin and Ecstasy.
"These are enormous amounts of narcotics, drugs otherwise destined for the streets of the United States," Holder said.
And Leonhart said that in addition to ramped up pressure on the cartels, the streets have felt the pinch: "The price of cocaine, in 24 months, has increased 104 percent, while the purity has decreased 34.8 percent."
In addition, agents have seized $59.1 million in cash, and an additional $6.5 million in assets, including 149 cars, three aircraft, three maritime vessels and 169 weapons.
The U.S. State Department has also warned of the situation throughout Mexico, cautioning U.S. citizens living in and traveling to that country to be vigilant.
"Mexican drug cartels are engaged in an increasingly violent conflict -- both among themselves and with Mexican security services -- for control of narcotics trafficking routes along the U.S.-Mexico border," the current alert says.
Kidnappings, daytime shootouts in public places and a "fluid" situation in northern Mexico have all contributed to the heightened security situation there, the warning states.
Juarez Mayor Seeks Refuge in El Paso
And in a startling example of the direness of the situation, the mayor of Juarez, Mexico is reportedly seeking refuge in this country as his family's only escape from threats of violence.
"We received information that the Juarez mayor lives in El Paso, and that possibly they were going to come to El Paso to get him," El Paso Police detective Carlos Carrillo said Monday. "He has not asked us for our help, but it's our duty to protect any resident of our city who may be under threat."
The State Department notes in its alert that "The situation in Ciudad Juarez is of special concern," adding that Mexican authorities have reported more than 1800 killings in the city of 1.6 million since January 2008. Car theft and carjackings in the area have also reached troubling levels, the warning added.
ABC News' Jason Ryan and Jack Date contributed to this report.