Tens of thousands of people have been killed in drug-related violence since Mexican President Felipe Calderonlaunched his military campaign against the cartels after he took office in late 2006.
Drugs were smuggled from Mexico into Arizona by car, plane, on foot, and through tunnels.
"This is one of the more substantial drug-smuggling operations going on right now. This is a billion-dollar drug trade organization linked to the cartel," the official said.
Further details of the operation will be released at a press conference at the U.S. Drug Enforcement Administration field office in Phoenix on Monday. The raids were overseen by the DEA, Arizona state officials, and the U.S. Immigration and Customs Enforcement agency.
Law enforcement officials in Arizona seized thousands of pounds of narcotics and arrested at least 70 suspected drug smugglers with apparent ties to a violent drug cartel in Mexico, an official involved with the investigation in the U.S. Southwest told Reuters on Sunday.
Officials arrest 70 in major Arizona drug bust

The operation, which included three raids conducted jointly by local, state, and federal officials over 17 months, led to the arrests of Mexican and American nationals working with the notorious drug cartel based in the Mexican state of Sinaloa, said the official, who spoke on condition of anonymity.
Authorities confiscated drugs, money, weapons, ammunition, and bullet-proof vests, cracking a "sophisticated network" of international drug smuggling in one of the largest such operations conducted in the Southwestern United States, the official said.
The cartel is headquartered in the northwestern state of Sinaloa on Mexico's Pacific coast, an area home to big marijuana and opium poppy plantations and considered the cradle of Mexican narcotics trafficking since the 1960s.
The cartel is believed to handle 65 percent of all drugs illegally transported to the United States, drug experts say.