The firms revealed last year that they planned a US joint venture, with production scheduled to begin in 2021.
At the time, President Donald Trump said the decision was “a great investment” in US manufacturing.
The choice for the factory location had reportedly been narrowed down to either Alabama or North Carolina.
One US media outlet reported that North Carolina missed out because it did not offer the supply-chain logistics the two firms required.
Tariff threat
The factory is expected to eventually produce 300,000 vehicles a year and employ about 4,000 people.
When contacted by the BBC, Toyota refused to confirm that Alabama had been selected, saying an announcement would be made “in early 2018”. However US media was widely reporting a formal announcement would be made on Wednesday.
The auto industry is one area where President Trump has been pressuring overseas companies to do even more manufacturing in the US.
Last year he said Toyota would face hefty tariffs on cars built in Mexico for the US market if they were made south of the border.
Research conducted by the BBC in November last year found that approximately 53% of cars sold in the US by the top six Japanese carmakers were made there.
The rest were made in Japan, Mexico, Canada, and elsewhere. (BBC)
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