The United Auto Workers will seek a commitment from General Motors to build new products at two idled plants in Tennessee and Wisconsin in upcoming contract negotiations, a top union official has said.

Reopening the plants is key to the UAW's strategy of focusing on jobs first and wages second in upcoming labour negotiations with the three major US automakers, Joe Ashton, the UAW's vice president for GM, was quoted as saying by Reuters.

Ashton said it would be easier to reopen the idled assembly line at its Spring Hill, Tennessee, plant where GM still builds engines, and has stamping operations and about 1,000 hourly workers.

There is no production at GM's plant in Janesville, Wisconsin, where a handful of workers secure and maintain the property.

"Product commitments equate to jobs, so that is exactly the direction we are looking at," in upcoming labour talks, Ashton told Reuters at GM's Orion Assembly plant near Detroit, which will begin making the Chevrolet Sonic and Buick Verano later this year.

"We're going to put a big emphasis on jobs," Ashton said, comparing this year's talks with those of four years ago when the UAW granted GM, Ford and Chrysler concessions during hard economic times.

"We could talk about wages, which is really important to our membership," Ashton added. "But if you don't have jobs, as you can see, wages really don't mean as much."

The union will go into talks "the same way we have in the past. But we do know it's a different time. We want to remain competitive."

The news agency noted that 40% of hourly workers at Orion will make what is called a second-tier wage, about half what the majority make.

The Orion plant is shown by the UAW and GM as an example of how jobs can be kept in the United States, due in large part to so many workers making the entry level wage of less than US$15 per hour.

Allowing lower wages at Orion Assembly, helped keep the jobs in Michigan, said Ashton of the UAW and Cathy Clegg, vice president for labour relations at GM.

Ashton said GM could have easily sent those jobs to Mexico or South Korea otherwise.