General Motors says it will sell in the United States next year a vehicle made in China, becoming the first major US automaker to do so.

The move was quickly denounced by the powerful UAW auto union, which branded it "a slap in the face" and called for an immediate rethink.

GM has sold 127,085 Buick Envision SUVs, made in the eastern province of Shandong, since January in China.

The automaker plans to import 30,000 to 40,000 of the vehicles each year, amid high demand for 4X4, crossover and pickup trucks in North America, as oil prices dip.

The controversial announcement comes as labor costs are set to rise for GM in the United States following a wage deal currently being finalized.

"Today's announcement by General Motors that they are importing the Envision from China is a slap in the face to US taxpayers and the men and women who worked so hard to save GM during its darkest time," UAW vice president and director of the General Motors Department, Cindy Estrada, said in a statement.

China became GM's biggest market last year, but a slowdown in the Chinese economy allowed North America to regain its top spot in the first nine months of 2015.

Last month, GM -- whose brands include Chevrolet, Cadillac and Buick -- sold more than 100,000 Buick vehicles in China, compared to 19,000 in the United States.