Inquiring about Death Certificates

If a person is an American citizen but is pronounced deceaced in another country (specifically Mexico) does the death certifacte used for legal purposes here issued from America or Mexico? Also If the dies there is the certificate they produce there sent here and then put on record here? Most importantly if I were to order this document from Mexico would it be written in Spanish? Or would this be optional? And what kind of information would I need to gain access to this record from the Mexican government? Do all the people that are American citizens or ever were excpted to be on record in the U.S as deceaced if they are?

Thank you.