Mexico on Thursday handed over major figures in the country's criminal underworld to U.S. authorities, part of a surprise extradition of nearly 30 jailed convicts or others accused of ties to violent drug cartels.

Mexico has sent 29 drug cartel figures, including drug lord Rafael Caro Quintero, who was behind the killing of a U.S. DEA agent in 1985, to the United States as the Trump administration turns up the pressure on drug trafficking organizations.

Mexico extradited more than two dozen cartel members to the United States on Thursday as the U.S.’s tariff implementation date approaches. The extradited figures include a cartel boss complicit in the murder and torture of a Drug Enforcement Administration agent in 1985.