Toyota already operates a broad network of factories in the US, but Mazda hasn't operated a plant there since exiting a long-running joint venture with Ford Motor Co. several years ago in southeastern MI.
North Carolina has four "megasites" that have been built to accommodate large industry such as automotive or airplane.
According to Bloomberg, the companies have narrowed the list for weeks, eliminating nearly a dozen other states that included Tennessee, Texas and SC. There are two megasites in Chatham County, one in Edgecombe County and one on the Guilford-Randolph counties border.
Activity at the site in recent weeks suggests that local officials are taking no chances.
Both Toyota and Mazda declined to comment to Bloomberg about the claims.
The factory is such a hotly contested prize that Toyota and Mazda are pressing for an incentive package valued at $1 billion or more. The news source reports MS was seen as an early contender for the plant.
By the time the plant opens in 2021, parts suppliers and other support operations would likely set up shop nearby, bringing more jobs. He has pressured auto companies to make more of their vehicles in the U.S. On his recent trip to Tokyo, Trump thanked executives from Toyota and Mazda for planning 4,000 new jobs at the plant, Bloomberg said.