Mexico City, Feb. 21 -- Mexican President Claudia Sheinbaum signed two constitutional amendments on Thursday to strengthen national sovereignty and impose harsher penalties on foreigners engaged in illegal activities in Mexico.

The move follows Washington's decision on Wednesday to designate six Mexican drug cartels as "terrorist organisations," a classification that could expand U.S. legal and military actions against them.

The president emphasised that while U.S. authorities can "name things however they want," Mexico operates on the principle of "collaboration and coordination, never subordination. No intervention, and certainly no invasion."

"We want to make it clear that we do not negotiate sovereignty," Sheinbaum said from the N...