Earlier quoted context omitted.
I missed the “different countries” bit. Hell no. OP, I hope you are on good terms with Trump, because you’re going to need that pardon.
This whole idea is dead on arrival because of this. Most nations actively warn their citizens never to carry packages from someone you don't know, and never to carry packages you didn't pack (or saw opened) yourself even for people you do know. And still people agree to carry sealed packages for someone they had a few nice nights with on holiday before boarding the plane back home. That tends to end in a little room…
I'd be hesitant taking anything from anyone, even a child handing a letter to be postmarked in Florida.