Parents approval for a marriage

I have two questions.

I met a guy who I am very in love with and we want to get married as soon as possible. His parents agree, my parents are divorced, and my mother agrees. But he is from a different nationality than I am and I am scared that my father will not accept. I know that this is not an acceptable reason to deny a marriage in Islam, but what are the exact hadeeth or ayat that I can mention in my argument?

My second question is, in the case that my father still wouldn't let me marry him, can I go ahead and marry him anyways given that the reason my father denied him (nationality) is a reason that is unacceptable in Islam?