United Auto Workers members leave the Fiat Chrysler Automobiles Warren Truck Plant after the first work shift on in Warren, Michigan, US, on May 18, 2020. [Photo/Agencies]

US automakers took the first steps to resuming production Monday amid continued concern for worker safety and a tattered national economy that's likely to undercut demand for new cars.

Many plants in Michigan and across the nation began with reduced shifts and, in some cases, fewer workers per shift after being closed for about eight weeks due to the coronavirus pandemic. Full production may not resume for several weeks, or perhaps months, officials said.

Worker safety is the immediate concern as production resumed at General Motors, Ford and Fiat Chrysler. But analysts expect automakers to build significantly fewer cars this year, cutting revenue.

"We have made it crystal clear to the companies that the health and safety of our members must be the top priority as we plan for the restart of our economy," Rory Gamble, president of the 400,000-member United Auto Workers (UAW), said in a statement.

Honda and Toyota resumed US production last week. Daimler, BMW and Hyundai restarted production in the last few weeks.

Resumption of production will test the new health and safety guidelines that automakers have developed in conjunction with the UAW. Many of the new safety procedures are built on China's experience and appear to work well.