Are you open to cross from Mexico to the United States?

It can be crossed if you are American. If you are Mexican with residence. But you cannot cross if you are Mexican with a tourist visa.

And

Crossing for visitors with a B1 and B2 tourist visa to the United States is still restricted. There is no crossing restriction for US citizens or residents. Passengers for a trip considered essential may also cross. For more information see https://www.dhs.gov/coronavirus/overview-dhs-response and the Official Notice of Temporary Travel Restrictions prior to your trip.

Yes

If only Americans can cross without problem