Negotiators previously had a fleshed-out NAFTA deal before Trump killed it - Canada Press

According to a report by The Ottawa Hill Times, a preliminary NAFTA deal was put before US President Trump earlier this month, including a desired compromise on automobiles.

"when the preliminary agreement was put before the president for his approval, he said he actually wanted something else."

 - The Hill Times

NAFTA negotiators had believed they were already working towards the US president's renegotiation goals. Trump's newer, updated version of the NAFTA agreement was outright rejected by Mexico, and talks have currently ground to a halt, which has been the impetus for the US' threats to impose stiff tariffs on foreign automotives.

The Hill Times speculated that Trump's goal is to push any sort of deal past the midterm elections in the US to avoid any deal criticism and keep his voting base on-edge in the run-up to the vote.