Which agreement? The Mexico/Guatemala agreement is in the link in post 36. That same temporary visa also applies to Honduras, El Salvador and anyone else that wants to use Mexico as a route into the US. Mexican citizens of course, don't need a Visa to cross Mexico so they can just flood right in. The internal US immigration rule is not an agreement or a law passed by congress. It's simply the administration issuing internal orders to the Border Patrol and INS. It's just another example of Obama ignoring constitutional law and doing whatever the hell he wants. The people don't want this. Congress doesn't want this. Only Emperor Obama wants this.
Not sure the equivalent could happen in Canada. Thinking/hoping Parliament would require a vote. edit: ugh, never clicked on the blue link KB. Maybe make it green. ..'Splains a lot, starting to sink in.