Some 10,000 U.S. hotel workers launched a multiday strike on Sunday in several cities after contract talks with major hotel operators including Marriott International, Hilton Worldwide and Hyatt Hotels reached an impasse, the Unite Here union said.

Unite Here, which represents workers in hotels, casinos and airports across the United States and Canada, said thousands of workers at 24 hotels are on strike in some major travel destinations including San Francisco and San Diego in California, Hawaii's capital city Honolulu, Boston, Seattle and Greenwich, Connecticut, with workers from additional cities ready to join the walkout as the Labor Day holiday weekend continues.

The strike is taking place with the industry facing a 9% increase in Labor Day weekend domestic travel compared to last year, according to AAA booking data.

"Strikes have also been authorized and could begin at any time" in Baltimore, New Haven, Oakland, and Providence, the union said in a statement, as hotel workers and operators struggle to agree on wages and on reversing pandemic-era job cuts.

Hotel workers are being stretched thin, according to the union, with management frequently assigning three staff members to do the job of four. This leads to undue stress and a focus on speed over service.

"Since COVID, they’re expecting us to give five-star service with three-star staff," the union said, quoting a staff member at Marriott’s Palace Hotel in San Francisco.

Hotel housekeepers in Baltimore are fighting to bring wages up to $20 per hour from their current $16.20. In Boston, where housekeepers make $28 per hour, the union is seeing a $10 per hour raise by the end of four years.

Hilton and Hyatt said they remain committed to negotiating a fair agreement with the union.

Hyatt has contingency plans in place to minimize the impact on hotel operations related to potential strike activity, Michael D'Angelo, head of labor relations at the luxury hotel chain said in a statement.

Marriott did not respond to a Reuters request for comment.

The strike comes as 40,000 Unite Here hotel workers across 20 cities face expiring contracts this year. Negotiations for new four-year contracts have been taking place since May, and about 15,000 of those workers have authorized strikes in 12 markets.

"We won't accept a 'new normal' where hotel companies profit by cutting their offerings to guests and abandoning their commitments to workers," Unite Here President Gwen Mills said, demanding a better deal.

The union has urged travelers to cancel their hotel stays if the workers are on strike and to demand penalty-free refunds.

Unite Here workers in 2023 won record contracts in Los Angeles following rolling strikes, and in Detroit after a 47-day strike.