Thousands of Amazon employees across the United States are preparing to strike during the peak Christmas season, following accusations from union officials that the company has refused to negotiate improved wages and working conditions.

The Teamsters union announced on Wednesday that warehouse workers in cities such as New York, Atlanta, and San Francisco will begin picketing at 6 a.m. Eastern Time (11:00 GMT) on Thursday. This action marks the largest strike against Amazon in the country's history.

"If your package is delayed during the holidays, you can blame Amazon's insatiable greed. We gave Amazon a clear deadline to come to the table and do right by our members. They ignored it," stated Sean M. O'Brien, Teamsters General President.

"These greedy executives had every chance to show decency and respect for the people who make their obscene profits possible. Instead, they've pushed workers to the limit and now they're paying the price. This strike is on them," he added.

The Teamsters union, one of the largest in North America, says it represents around 10,000 of Amazon's approximately 800,000 workers in the United States.

In a press release, the union described the walkout as the "largest strike against Amazon in U.S. history," stating that it follows the company's refusal to negotiate with workers represented by the Teamsters.

In a statement to ABC News, an Amazon spokesperson accused the Teamsters of illegally pressuring workers to join the union.

"For more than a year now, the Teamsters have continued to intentionally mislead the public - claiming that they represent 'thousands of Amazon employees and drivers.' They don't, and this is another attempt to push a false narrative," said Amazon spokesperson Kelly Nantel.

"The truth is that the Teamsters have actively threatened, intimidated, and attempted to coerce Amazon employees and third-party drivers to join them, which is illegal and is the subject of multiple pending unfair labor practice charges against the union."

The spokesperson also highlighted that the company has raised the starting minimum wage for fulfillment center and transportation workers by 20% and, as of September, increased the average base wage to $22 per hour.

Amazon's Staten Island facility in New York City became the company's first unionized warehouse. Employees there have claimed that Amazon has refused to acknowledge the union or negotiate a contract after their unionization vote in 2022.

The National Labor Relations Board formally recognized the union representing workers at the Staten Island facility, but Amazon has filed an appeal against the decision.