Mexico has extradited 29 suspected drug traffickers, including key cartel members, to the United States.
The move comes as Mexico seeks to reach a deal with the US to avoid punitive tariffs.
President Donald Trump has threatened tariffs on Mexican goods if the country does not increase efforts to stop migrants heading to the US and combat the smuggling of fentanyl.
Among those extradited are Rafael Caro Quintero, founder of the Guadalajara Cartel and suspected of kidnapping, torturing, and killing a US agent in the 1980s, and Vicente Carrillo, former head of the Juárez Cartel.
The head of international operations for the US Federal Drug Enforcement Administration (DEA) described the extradition as historic, noting that Mexico has typically extradited only a few suspects at a time.