The United Auto Workers and General Motors have reached a tentative deal to end the union's four-week strike against the automaker.

Details of the deal were not immediately available, but a statement from UAW said "the agreement represents major gains for UAW workers."

"The No. 1 priority of the national negotiation team has been to secure a strong and fair contract that our members deserve," UAW Vice President Terry Dittes, director of the UAW GM Department, said. "Out of respect for our members, we will refrain from commenting on the details until the UAW GM leaders gather together and receive all details."

"We can confirm the UAW’s statement regarding a proposed tentative agreement. Additional details will be provided at the appropriate time," a statement from GM said.

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The strike will continue until at least Thursday when the UAW's GM national council will meet to review the deal and vote on whether to present it to UAW-GM's full membership for ratification.

The council will also decide during Thursday's meeting whether to continue to strike until "membership across the U.S. votes to approve it" or end the strike when the council approves of the deal.

“The dignity, grace and solidarity demonstrated by our members during the last few weeks are prime examples of what this union is all about — supporting one another in the good and bad times and never giving up,” UAW President Gary Jones said.

About 48,000 United Auto Workers members officially began striking Sept. 15 at 11:59 p.m. ET after negotiations faltered between the union and General Motors.

The two sides weren't able to agree on wages, health care benefits or profit-sharing, Dittes had said in a statement.

He said before the strike began that the decision for workers to walk off the job was a “last resort.”

Other sticking points included getting GM to pledge to keep production in the U.S. and commit to hiring long-term temporary workers, who make less money and have different benefits, as full-time employees. Also on the table were 3 percent raises and lump sum bonuses in two of four years and better health care at no extra cost, according to NBC affiliate WDIV in Detroit.

The union was also seeking job security.

GM CEO Mary Barra has handed out pink slips to thousands of workers in recent months and closed four U.S. assembly plants as part of a restructuring that GM said saved the company $1.1 billion in the first half of 2019 and $700 million in the second quarter of this year. GM has made $27.5 billion in profits over the last four years of the expired labor contract.

About 200 local union leaders had unanimously voted for the strike, which affected dozens of facilities across the country.

A worker gestures to passing motorists outside of the General Motors facility in Langhorne, Pa., during a United Auto Workers strike on Sept. 17, 2019. Matt Rourke / AP

General Motors said when the strike began that the company had put forward a "fair offer" that included “best in class wages” and “nationally leading health care benefits.”

In the midst of the strike, GM dropped health care plans for workers who had walked off the job. “We understand strikes are difficult and disruptive to families,” GM said in a statement. “While on strike, some benefits shift to being funded by the union’s strike fund, and in this case hourly employees are eligible for union-paid COBRA so their health care benefits can continue.”

Workers received their last paycheck during the week the strike began and since then had to manage on $250 per week in strike pay, which did not kick in until the eighth day of the strike.

The Detroit automaker also temporarily laid off about 4,500 Canadian autoworkers as some operations halted there as a result of the strike.

Wall Street analysts estimate the strike cost GM between $50 million to $100 million per day in lost production, according to CNBC. The last time UAW declared a national strike at GM was in 2007, when workers walked off the job for two days.

At the beginning of the strike, President Donald Trump encouraged the two sides to continue negotiating, saying in a tweet: "Here we go again with General Motors and the United Auto Workers. Get together and make a deal!"

Democratic presidential candidates, former Vice President Joe Biden, South Bend, Indiana, Mayor Pete Buttigieg, former Housing Secretary Julián Castro, Sens. Elizabeth Warren, Bernie Sanders, Amy Klobuchar and Kamala Harris all backed the union in tweets. Some also joined the strikers in picket lines.

The strike began weeks after federal authorities reportedly raided the home of UAW president Gary Jones. The raid appeared to be part of a corruption probe that included the arrest of Vance Pearson, a member of the union’s international executive board, on charges of embezzlement.