Trump announced he and the EPA are re-examining midnight hour Obama-era federal requirements on fuel economy standards requiring a fleet-wide average of 36 mpg in real-world driving by 2025 for cars and trucks. A rollback is expected no later than April 2018.

"The assault on the American auto industry is over," as Trump put it in his speech at a former GM plant that's part of the American Center for Mobility, which is a staging ground for self-driving vehicles.

Trump told auto CEOs that they "have to build plants here." He added, "I know I gave you a hard time but you have to build them here," according to The Washington Post. He also gave a classic campaign-style speech, harping on NAFTA and the TPP.

Trump is en route to Nashville to lay a wreath on Andrew Jackson's tomb to mark what would be his 250th birthday.

What to watch: Trump announced he will have a "big" auto industry announcements next week about jobs.