The U.S. Embassy in Mexico City and all other U.S. consulates general in Mexico suspended routine consular and visa services on March 18, 2020 due to COVID-19. The pandemic is still ongoing.
Effective October 20, 2020, the U.S. Embassy in Mexico City and Consulates General Guadalajara, Hermosillo, Matamoros, Merida, Monterrey, Nogales, Nuevo Laredo, and Tijuana resumed limited appointments for some routine passport, citizenship, and notarial services. This does NOT include appointments for those pursuing immigrant visa processing (consular processing).
Some appointments are available on an emergency-basis only at certain locations, including the Consulate General post in Ciudad Juarez. Immigrant visa (consular processing) emergency appointment requests will be considered only when the applicant will age out of his or her case, or in special case emergencies.
More information regarding closures and suspension of services in Mexico due to the ongoing pandemic can be found here in both English and Spanish: https://mx.usembassy.gov/status-of-u-s-consular-operations-in-mexico-in-light-of-covid-19/.