Upvote:1
Salut alon !
Unfortunately, you cannot apply for a B2 visitor visa while in the US. You would have to go to a US consulate in Mexico (or some other country) and apply as a "Third Country National."
If you were to go to a consulate in Mexico, there is an application process here
http://mexico.usembassy.gov/visas/non-immigrant-visas/how-to-apply.html
Bonne chance, et courage !