The U.S. and Canada are clearly the model for the world. The U.S. has other pre-clearance agreements that are limited with other countries, and which are much newer than the Canada-U.S. one, but the Canada-U.S. agreement is light years ahead of anything else that the U.S. would consider. It's not the same as an EU model, for example, as between the Europeans, but that's an entirely different agreement and arrangement that takes on a lot of other things. When you're talking about the United States and a reciprocal agreement with the United States, the Canada-U.S agreement is light years ahead of any others that the United States would have.
On May 29th, 2017. See this statement in context.