[longtermmemmory]

Unless contradicted by treaty, every non-resident alien has to have a passport, a visa, and a I-94 card (says how long they are allowed to stay pursuant to their visa). For example a B1/B2 visa can be good for 10 years but each trip can only be 3 -6 months max.

The consular matricula is an underhanded and illegal means of bypassing US/mexican treaty.

[proxy_user]

I think there are some countries from which no visa is required for a stay of less than three months, such as the UK.