The new US immigration law inside the new trade agreement with Canada and Mexico says if you cross illegally into America thru Mexico or Canada, the United States government will now deport you back to either Mexico or Canada where you come from illegally not your country of origin.
To save cost, and punishment meaning Mexico and Canada can no longer make it possible for illegal immigrants to use their countries as a gateway to America without paying a price for the relaxation of their immigration policy that undermines America immigration system.
Secondly, it will also affect the immigration numbers of Canadians and Mexicans coming to America meaning if they are too careless, their own citizens will have their quotas reduced by the numbers of illegal immigrants through their countries.
Those two items are within the USMC trade agreement that replaced NAFTA.
The above is making Mexico for the first time to set up immigration camps and asking for help from UN for refugees coming like caravans coming Honduras, Columbia and other Central Latin American countries using Mexico to cross into America.
Expect some changes in visa requirement of Canada and Mexico when next you visit their embassies.
The new policy is how the present administration is getting around catch and release system which is a mockery of the immigration policy in favor of the Democrats that refused to fund the border wall of Trump administration.