working again in the US as a TA.

Ten years ago I worked for two years in the US as a teacher assistant, when I moved back to Mexico and started looking for a job as an English teacher my previous experience (working in the US) was really taken in consideration, but know after six years working in Mexico, with all the hard work ( report cards, plannings,exams etc.) that a teacher does, I want to go back to the US and start working again as a TA, but this seems so difficult to achieve. Don't wet me wrong, but I get the feeling that working in Mexico isn't considered a job experience when it comes to looking for a job in the US.