The new agreement extends free trade between the U.S., Canada and Mexico with a few tweaks.
Congressional Democrats have suggested they could vote for the North American pact if protections for Mexican workers are sufficiently implemented.
Canada's Prime Minister is in DC Thursday talking trade and the "new NAFTA".
The Trump administration has threatened to levy a 5% tax on Mexican imports next month, which could go as high as 25%.
Signed but not yet delivered: The new NAFTA isn't very different from the old one.