United States federal law enforcement agency under the U.S. Department of Justice tasked with combating illicit drug trafficking and distribution within the U.S. It is the lead agency for domestic enforcement of the Controlled Substances Act, sharing concurrent jurisdiction with the Federal Bureau of Investigation, the U.S. Immigration and Customs Enforcement, and U.S. Customs and Border Protection. However, the DEA has sole responsibility for coordinating and pursuing U.S. drug investigations.