Can I join the Military Academy or a ROTC Program at a College without being an US Citizen?

I am a permanent resident and I have a social security number/card and my green card however I am not considered a citizen. Even so, will I be allowed to apply to a Military Academy after I graduate Highschool? if not, what about a ROTC program at a normal College like UC irvine? I will become a US citizen but not before I apply.