Now that President Donald Trump has symbolically signed the revised North American trade agreement at the G-20 summit in Argentina, he moves a step closer to delivering on a campaign promise -- to replace NAFTA or terminate it -- after a week fraught with negative economic headlines.

Just Tuesday, General Motors announced that, in light of the new deal, it was laying off 15 percent of its workers and shuttering five plants in the U.S. and Canada.

The president had boasted that the renegotiated and renamed USMCA deal -- the U.S. Mexico Canada Agreement -- would have just the opposite effect.

"He believes -- as, frankly, the prime minister of Canada, Trudeau, believes -- that the USMCA deal was a great help to the automobile industry and to autoworkers," Trump's economic adviser, Larry Kudlow, said, reacting to GM's decision. Read More