If I buy a Steam wallet card in the US, can I activate it Mexico?

[Estemma]

Hello people, I have searched this question, some say steam cards are global, others say that don't work on other countries. I have a ps3 and I like to buy psn cards in the US and activate the codes here in mexico, However, you need to have an account in the U.S to be able to redeem the codes. I thought in doing the same for the steam cards, but I found that Steam automatically detects your country and don't ask you where do you want to create the account. Currently, steam doesn't accept Mexican currency, I think that is why they don't accept safepay cards from Mexico, I know they are planning to add the currency, but I think games will still be cheaper for you guys living in the US.
Have you ever done this?

P.S. I was trying to find a simple way to buy in steam without banks.
Thanks for your answers in advance. :)

[Doomy4Life]

I dont know if this will help, but USA cards work in Canada. Your just on the other side of USA so I would assume they work too

[Estemma]

I read they are planning to add the Canadian dollar too, everyone is fearing that the prices will go up.