López Obrador has faced criticism from US officials for his comments, which some have called insensitive and unhelpful in addressing the crisis. However, he has stood by his claims that Mexico's close-knit family values have helped to protect the country from the wave of fentanyl overdoses.
"There is a lot of disintegration of families, there is a lot of individualism, there is a lack of love, of brotherhood, of hugs and embraces," said López Obrador. "That is why they [US official] should be dedicating funds to address the causes."
Despite López Obrador's denial that Mexico produces fentanyl, US authorities estimate that the majority of illegal fentanyl is produced in clandestine labs in Mexico. The drug is often pressed into counterfeit pills that resemble other medications.
López Obrador also argued in favour of a Mexican-US ban on using fentanyl in medicine. Although little of the drug crosses leaks hospitals.
Experts blame Mexican cartels for trafficking the synthetic opioid, which is responsible for around 70,000 overdose deaths per year in the US, according to recent statistics. The cartels are said to make significant profits from the US market, leading them to focus their efforts on that region rather than their home market in Mexico.
The US government has been working to address the crisis, with actions including considerations of designating Mexican drug gangs as terrorist organizations.