As far as I know, yes, there is always a fee of some sort when the sender and receiver are not in the same country (regardless of the currency.)

I cannot say with 100% certainty that there is fee in the situation you described, but I can say with 100% certainty that there is a fee in the reverse situation.

In other words: If I am sending USD via F&F to a US-based recipient, I get charged a fee, because my account is based in Canada.