Hi Knight2017,
Are you asking about the funds offered by the company American Funds? Or are you asking about 'American Mutual Funds' in general? :-)
Assuming that you are asking about the mutual funds offered by American Funds, then the answer to your question depends on your residency status rather than your nationality. Do you mean that you are a Canadian and live in Canada, or that you are a Canadian living in the US?
Generally speaking American Funds is not able to open accounts for non-resident aliens becuase of difficulties in tax reporting. (However it is possible for a previously resident aliens who subsequently become non-resient aliens to keep their American Funds).
I am a resident alien here in US and hold American Funds. I am also an employee and would definitely agree with the post above - call the 1-800# and ask to speak with an associate trained on foreign accounts and they will be able to advise you fully.