The union that represents Starbucks baristas across the country announced that members in Los Angeles, Chicago and Seattle will go on strike in the days leading up to Christmas.

Workers United, which has unionized more than 525 Starbucks locations across the U.S., said in a news release Thursday that unfair labor practices and stalled negotiations with the company prompted the Christmas strike.

The union says five days of escalating strikes will begin on Friday and continue until December 24 in “three of the company’s priority markets”, during what are the busiest days of the year for the company.

During the strike period, strikes are expected to “increase day by day, eventually reaching hundreds of stores coast to coast by Christmas Eve” unless the company honors a commitment made with the union in February.

In February 2024, Workers United and Starbucks announced they were working on a “basic framework” to reach a store collective bargaining agreement, but that did not come to fruition, according to the union.

In a statement Thursday after announcing the strike, Starbucks said Workers United delegates had “early terminated” negotiations with the coffee giant this week.

Starbucks added that the company is “focused on improving” the employee experience by offering an average wage of $18 an hour and benefits such as health care, free college tuition, paid family leave and company stock grants.

“We stand ready to continue negotiations to reach agreements,” Starbucks said, adding: “We need the union to come back to the table.”

However, Workers United said that Starbucks had not yet made a “serious economic proposal” to workers, despite having “repeatedly publicly promised” that it would reach contracts by the end of the year.

“Nobody wants to strike. It is a last resort, but Starbucks has broken its promise to thousands of baristas and left us with no other choice,” Fatemeh Alhadjaboodi, a five-year Starbucks barista and negotiating delegate, said in the press release.

“In a year in which Starbucks has invested so many millions in top executives, the company has failed to provide a viable economic proposition to the baristas who keep its business running. This is just the beginning. We will do whatever it takes to get the company to do this.” “We will honor the commitment made to us in February,” Alhadjaboodi added.

“The holiday season at Starbucks should be magical, but for too many of us, the peppermint mochas and gingerbread lattes have a darker side,” said Arloa Fluhr, a negotiating delegate who has worked at Starbucks for 18 years, according to the release.

“I am a mother of three children, including my daughter who is diabetic. I know what it’s like to panic because my hours have been cut and I won’t be able to pay my bills and potentially lose access to healthcare, including my daughter’s insulin.” “That’s why we remain steadfast in our demand that “Starbucks invested in baristas like me,” Fluhr added.

ABC News’ Zunaira Zaki contributed to this report.