Designating groups as foreign terrorist organizations is aimed at disrupting their finances through the imposition of U.S. sanctions. While it does not directly give authority for overseas military operations, many Mexicans are nervous that it would lead to unilateral U.S. action against gangs.

“Since 1914 there hasn’t been a foreign intervention in Mexico and we cannot permit that,” Lopez Obrador said at a regular news conference, referring to the U.S. occupation of the port of Veracruz 105 years ago.

“Armed foreigners cannot intervene in our territory,” he said, instead offering more cooperation with the United States on fighting drug gangs, which have shown their power with a series of battles with security forces and civilians in recent months.