It was only recently that Greece stopped openly calling for enosis, enjoining Cypriots to overthrow their own government if necessary. They've been quieter about that crap over the last couple of decades, but Greece still clings to the territorial dispute to justify its overgrown military. It is quite accurate to say that Greece hasn't yet let go of Cyprus, and that doing so would save it considerable money.
To my knowledge, the U.S. has never encouraged Canadians to overthrow their government, nor do they use Canada as an excuse to justify an expensive cold war against, say, France.
The Republic of Cyprus is a sovereign state, it's not part of Greece.