As a general principle of law-making, the Parliament of Canada can only make laws that apply in Canada. In terms of this proposed amendment that relates to international agreements, any potential applications of those international agreements would only be as they apply in Canada, so it would be agreement by agreement to look at what the implications would be.
We did get the answer for you, thanks to my colleagues. The United States does support the United Nations Declaration on the Rights of Indigenous Peoples, but I do not believe that it's part of their law.