The United Auto Workers union (UAW) plans to further expand its strike against Detroit's legacy automakers on Friday if labor talks don't make significant progress.The auto union said the announcement will be made at 10 a.m. ET on September 29 during a Facebook Live event hosted by UAW President Shawn Fain. The deadline for extending the strike is noon that day.

Currently, the UAW's strike against Detroit's three major auto giants - Ford, General Motors and Stellantis NV - has lasted for nearly two weeks, but negotiations have still failed to achieve a breakthrough.

The strike was launched on September 15 and expanded for the first time a week later (September 22). At that time, the UAW announced that it would expand its strike against the Detroit automaker's assembly plants to 38 additional parts and distribution locations for General Motors and Stellantis. The union stopped short of expanding its strike against Ford, citing progress in negotiations.

Unlike previous strikes, UAW leaders have chosen to conduct targeted strikes at selected plants rather than launch a nationwide strike.

Currently, the strike involves about 18,300 workers, accounting for 12.5% ​​of the 146,000 UAW members whose labor contracts expired on September 14. Striking workers receive $500 a week from the UAW's strike fund. Fain previously said the union planned to expand the scale of the strike depending on the progress of negotiations with the car companies.

Although the automaker made a record contract offer that included a roughly 20% increase in hourly wages, thousands of dollars in bonuses, union-preserving platinum health care and other fringe benefits, the union was not satisfied.

The main demands put forward by the union include a 40% salary increase, a 32-hour work week, the restoration of the traditional pension system, the elimination of pay grades, and the restoration of cost-of-living adjustments.

So far, the UAW and auto companies remain far apart on key economic issues.

President Joe Biden joined auto union members on Tuesday, becoming the first sitting president to join striking auto workers on the front lines of a strike. Biden also said he supports the union and its demands, including a 40% wage increase over the life of the contract.

The UAW's next potential strike targets include engine and transmission plants, as well as plants that make large pickup trucks and SUVs.

A broader strike that halts production of large pickup trucks and SUVs could cost automakers billions of dollars in lost revenue and profits. Analysts estimate that GM, Ford and Stellantis each generate as much as $15,000 in profit per vehicle on their large pickup models.