BD, legal help's link is simply amazing! I've come to know more about F1 situations. But do you really need to go out of the country? Can you not stick around with an approval of some extension until you decide to go to Nepal (or some other country) out of some really exciting necessity rather than for restamping your (new) passport? Will you share your actual situations in more details? Unless you are thinking of enjoying salsa there in Mexico as a primary objective of your visit there... As long as every thing goes well, so much the better. If these border guards or the consul there turn out to be nasty to you, you will be forced to enjoy a long flight to Nepal at your own cost, which is pretty expensive.