I'm not sure what the possible confusion is, but when Americans say North America, they mean the continent and it is often used mainly to include Canada, although there are many other countries in North America, including Mexico. If we are referring to the geography of the US, we would say Northern US. Those of us who are mindful of the fact that we are not the only country occupying the continent often try to avoid saying "America" for the country (especially when we are in Canada) and use United States or US instead, although we do refer to ourselves as Americans.
And an interesting tidbit that we all learn in primary school: our continent was named for an Italian, Amerigo Vespucci.