"Deliverance continues a deliberate and strategic effort to cut off and shut down the supply of drugs entering our country, and the flow of drug profits and guns to Mexico," she said. "The stakes are extraordinarily high, and this massive operation is a milestone in our tireless assault on these violent drug cartels."

Mrs. Leonhart, joined by Attorney General Eric H. Holder, Jr., said during a Justice Department press conference that more than 3,000 federal, state and local law enforcement agents and officers took part in the investigation.

Overall, she said, the operation accounted for $154 million in cash, 1,262 pounds of methamphetamine, 2.5 tons of cocaine, 1,410 pounds of heroin, 69 tons of marijuana, 501 weapons and 527 vehicles.

Arrests were made or charges were filed in Maryland, Virginia, Arizona, California, Colorado, Florida, Georgia, Illinois, Missouri, Montana, Nevada, New Mexico, New York, North Carolina, Pennsylvania, Tennessee, Texas and Washington state.

It was not immediately clear how many of those arrested were U.S. citizens or how many were illegal immigrants.

Mr. Holder described the operation as one of the "most extensive and most successful" in history.

"This successful operation, however, is just one battle in an ongoing war," he said. "So long as cartels and smugglers attempt to wreak havoc on our borders, we will continue to target them with every resource available to the federal government."

Mrs. Leonhart said that as part of bilateral efforts between Mexico and the United States to disrupt drug cartel operations, Mexican law enforcement provided "significant supportive actions" for the investigation.

She noted that among those arrested was Carlos Ramon Castro-Rocha, a suspected heroin smuggler who has been designated by the U.S. government as a leader of a drug trafficking organization responsible for the importation of large quantities of narcotics into the United States.

Mrs. Leonhart said Mr. Castro-Rocha was arrested by Mexican authorities on May 30 based on a U.S. warrant sought after he had been indicted in U.S. District Courts in North Carolina and Arizona on drug trafficking charges.

Those arrested in Project Deliverance were charged with conspiracy to distribute methamphetamine, cocaine and marijuana; distribution of methamphetamine, cocaine, heroin and marijuana; conspiracy to import narcotics into the United States; and other violations of federal law.

Mrs. Leonhart described Project Deliverance as part of the Southwest Border Strategy announced in March 2009 that uses federal prosecutor-led task forces that bring together federal, state and local law enforcement components to identify, disrupt and dismantle Mexican drug cartels. She said the operation targeted key cartel leaders and facilitators, and sought to seize their assets.

The investigation was coordinated by the multiagency Special Operations Division, composed of agents and analysts from the DEA, FBI, U.S. Immigration and Customs Enforcement, the Internal Revenue Service, U.S. Customs and Border Protection, the U.S. Marshals Service and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Also involved were Justice Department criminal division attorneys from the narcotic and dangerous drugs section. More than 300 federal, state, local and foreign law enforcement agencies contributed investigative and prosecutorial resources to Project Deliverance, many of which were through the High Intensity Drug Trafficking Area Task Forces and the Organized Crime Drug Enforcement Task Forces.