At what age is Roman alphabet being taught in your country?

I would like to address this question to Russian, Arabic, Greek, Jewish, Chinese, Japanese, Hindi, Korean, Thai and other users whose language require characters other than Roman ones.

I am interested in knowing how soon kids at grade school or even kindergarten get to learn Roman alphabets. I would also like to know from your first-hand experiences the difficulties you encountered in tackling two types of scripts.

Thanks a lot.