Wifredo Ferrer said cocaine and other illegal drugs still come to the United States primarily through Colombia to Mexico and across the Southwest border, The Miami Herald reported.
But, he said: "We're hitting them hard there. It's only a matter of time before we see an increase here.''
Speaking to reporters in Miami Thursday, Ferrer announced the "Caribbean Basin Initiative,'' which will add two more federal prosecutors for narcotics cases who will work with federal agents to combat an expected increase in drug trafficking.
For years, the Herald said, Colombian smugglers have used the Caribbean to ship cocaine into the United States, mainly through Haiti, the Dominican Republic and the Bahamas.
The newly announced anti-smuggling effort came six months after Ferrer unveiled an initiative against Colombian traffickers. It focused on 30 groups trying to replace cartels in Medellin, Cali and the North Valley of Colombia that officials say have been largely dismantled.
In the earlier effort, four new prosecutors joined DEA, FBI and Immigration and Customs Enforcement agents who worked with Colombian authorities to target criminal organizations.
The initiative has led to indictments of more than 100 people in Miami, Ferrer said.
"We still see the majority of cocaine coming into the United States across the Southwestern border," said Mark Trouville, DEA special agent in charge. "But the more our efforts increase there, the more we worry here."