It is not just tied to folks who have come through the American border, but the likelihood is that we would see a significant further increase in the number of people who seek to come to Canada for the purpose of making an asylum claim.
For people who wish to come to Canada, we want to encourage them to use regular migration pathways and discourage them from making an asylum claim unless they must. We really do abide by the principle where we encourage people to make an asylum claim in the first country where they are safe, because travelling through a country without status—though they may not be in a particular danger—is still not always a safe thing to do for individuals and for families.
I expect that simply suspending the safe third country agreement would result in a significant increase of people making, in many instances, very dangerous journeys—not just through the United States, by the way, but through many other countries—on a potential pathway to Canada.