IATA (International Air Transport Association) code would be MEX.
If you refer as local abbreviations, there is no official one, but most Mexicans know Mexico City as Mexico, "Ciudad de Mexico" or "La Capital".
It is CDMX (It stands for Ciudad De MeXico).
ANSWER:The standard two letter abbreviation for the state of New Mexico is NM. The abbreveation for Mexico is MX.
NMNM as in New Mexico
MT is the abbreviation for Montana.
USA
MEX or MX is such abbreviation.
New Mexico
Mexico City.
Mexico City
The abbreviation is L.A.
Mexico City, Mexico
The abbreviation for Salt Lake City is SLC.
Mexico City is in Mexico.