Amazon.com Inc. workers at the company’s sole unionized warehouse in the US joined a broader strike by the International Brotherhood of Teamsters.

The union is aiming to pressure the online retailer by threatening delays in package deliveries during the critical holiday season.

A spokesperson for Amazon said the union claims they represent “thousands of Amazon employees and drivers” when they don’t.

The Staten Island Amazon facility, known as JFK8, employs more than 5,000 workers, and about 100 of them joined the picket line early Saturday.

Bundled up and huddled around propane and diesel heaters, the group appeared upbeat and optimistic as strike organizers provided them with hats, jackets, hand warmers, beverages and snacks.

Amazon workers at four California facilities will join their striking colleagues on the picket line Thursday morning after reaching a stalemate during labor negotiations.

The Teamsters said the strike will begin Thursday at several facilities, including in New York City, Atlanta, California and Illinois.

The International Brotherhood of Teamsters said workers at seven Amazon facilities will begin a strike on Thursday morning.

The Teamsters' strike against Amazon began Thursday morning at several facilities in New York City, Atlanta, California, Illinois and elsehwere.

Amazon workers have walked off the job at seven facilities throughout the U.S., including the company's Queens location in New York City, as they push for contract talks with their union.

Union organizers have called an end to a five-day strike against Amazon by about 100 Atlanta drivers who joined other workers around the country