Traveling on U.S. Passport/Staying in Mexico/Need chinese Visa....

I work for the cruise industry and I have a 6 week vacation that I plan to spend all of it in Mexico City. I will need to obtain a Chinese Visa for my contract. Can I apply while in Mexico City or do I have to go all the way back to the states to apply? i will be traveling in Mexico only on a standard Tourist Visa good for 6 months..

Thanks in advance,