The US designating them as terrorists would allow the US to go in and remove the threats just like any other cell.
Cooperation of the Mexican government is ideal and could be done through economic leverage like the last admin did with the USMCA to get the Stay in Mexico policy and Mexican troops on the border.
It's one thing to f-up small countries in the other side of the world, but doing that to a neighbor almost half your size, with a huge shared border, impossible to land lock, and with millions of sympathizers residing in your own territory... you don't want a giant Afghanistan/Cuba as your roommate.
So if you're against the US picking these cartel members up the armed way, what method would be more effective or is the current status quo okay?
Please stick to the discussion next time though, instead of attacking the person, it shows weak emotional control, it's rude, and it's immature.
Plus ya'know, it violates this site's guidelines.