General Motors plans to spends US$1bn in Mexico to produce electric vehicles, a move that has angered US unions, according to media reports.

CNBC noted the spend at Ramos Arizpe was the first major GM announcement for EV production in Mexico following billions of dollars in confirmed investments for the US and Canada.

GM said the factory would begin producing at least one EV from 2023 but no more details were forthcoming, CNBC said.

The currently produces the Chevrolet Equinox and Chevrolet Blazer SUVs plus engines and transmissions.

Former US president Donald Trump was well known for his opposition to plants in Mexico supplying cars for the US. CNBC noted GM’s announcement came amid a push from the Biden administration for automakers to increase American manufacturing, including EVs.

GM did not announce whether the EVs would be imported into the US, the report added, however current products produced at the plant are sold in America.

United Auto Workers vpresident Terry Dittes told CNBC the investment was a "slap in the face" to its union members and US taxpayers as the company is one of many lobbying for government incentives to support EVs.

Dittes said taxpayer money "should not go to companies that utilise labour outside the US while benefiting from American government subsidies."

In the press release cited by CNBC, Francisco Garza, CEO of GM operations in Mexico, thanked the federal and local governments for "promoting" the investment. The company did not disclose specific details of the government support.

The investment includes new capacity for battery packs and other electronic components such as electric motors, which will begin during the second half of this year. It also includes a new paint shop, which is scheduled to begin operations in June, according to the translated press release from the company.

CNBC said the Ramos Arizpe plant was expected to be GM's fifth manufacturing site in North America to produce electric vehicles following announcements for two plants in Michigan and others in Tennessee and Ontario, Canada.