Maybe he could and it wouldn't be the first time Canada played hard ball with the US and won. Back in the 80's or 90's Canada wanted the US to sign a off shore fishing agreement but they refused. So Canada said - well if you don't sign the papers we might not re new your lease for the Nanoose Bay Maritain Test Range - the next day the US signed the papers. There is only 10 years left on the new lease so maybe Trudeau can remind Trump about that at the Northern Border wall meeting,
i never wanted Trudeau as a Prime minister, but i dont think he have that in mind so its nice. anyways there been thousand and thousands of migrants coming from the US border to canada to get citizenship.. after trump was elected...