TAPACHULA, MEXICO -- Mexican authorities have detained a Guatemalan man wanted by the United States for allegedly participating in the importation of precursor chemicals used by the Sinaloa cartel to make fentanyl, officials said Monday.

Immigration authorities stopped Jason Antonio Yang López at the airport in Tapachula on Sunday and turned him over to agents from the Chiapas state prosecutor鈥檚 office, according to two officials in the prosecutor鈥檚 office who requested anonymity because they were not authorized to discuss the case.

Yang López was being processed on organized crime charges, one of the officials said. Tapachula is just across the border from Guatemala.

In January 2023, the U.S. Treasury鈥檚 Office of Foreign Assets Control sanctioned Yang López 鈥渇or aiding in the procurement and importation of fentanyl precursor chemicals into Mexico for manufacturing, with the final product arriving in the United States.鈥

The sanction blocked any property and assets Yang López had in the United States. U.S. officials said the precursors were imported from a chemical company in China.

Fentanyl is the deadliest drug in the U.S. today. The Centers for Disease Control and Prevention estimates that 71,000 people died from overdosing on synthetic opioids such as fentanyl in 2021, compared with almost 58,000 in 2020.

Mexico and China are the primary source countries for fentanyl and fentanyl-related substances trafficked directly into the U.S., the U.S. Drug Enforcement Administration says. Nearly all the precursor chemicals that are needed to make fentanyl are coming from China.