US and Mexican law enforcement authorities will set up a joint team based in Chicago targeting the leaders and finances of drug cartels that ship opioids into the United States, aiming to reduce overdose deaths.
The announcement of fresh co-operation on security issues comes at a time of strained relations between the two neighbouring countries and around four months before President-elect Andres Manuel Lopez Obrador, a left-leaning nationalist, is due to take power in Mexico.
"We are sure the next president of the republic will be willing to collaborate in the fight against organised crime," Felipe de Jesus Munoz Vazquez, Mexico's deputy attorney general for invesigating federal crimes unit, told a joint US-Mexican news conference in Chicago.
Targeting cartel finances is key in stopping the flow of drugs because "the sole purpose of these entities is one thing and one thing only - money," said Anthony Williams, chief of operations for the US Drug Enforcement Administration.
Mexico remains the principal highway for cocaine to the United States and has become the top source of heroin, which is fuelling a surge in opioid addiction in the United States. It is also a major supplier of methamphetamines.
Chicago Police Superintendent Eddie Johnson said Mexican cartels were responsible for much of the illegal drugs flowing into the nation's third-largest city, which has been plagued by gang violence and shootings.
On Wednesday, Mexico said it was offering a 30 million peso ($A2.2 million) reward for information leading to the arrest of Nemesio Oseguera, whose cartel is blamed for driving heroin shipments to the United States.
In March, US agents in Chicago named El Mencho public enemy No. 1 and have also offered $US5 million ($A6.9 million) for information leading to his capture.
