WASHINGTON, Feb 28 (Reuters) - President Joe Biden defended workers' right to unionize and urged them to "make your voice heard" in a video statement posted on Twitter on Sunday night, as Amazon.com Inc employees in Alabama vote on whether to unionize.

Biden didn't mention Amazon, but specifically referenced "workers in Alabama" in the video and a tweet introducing it. "The choice to join a union is up to the workers full stop. Full stop," he said.

"Unions lift up workers, both union and non-union, but especially Black and Brown workers," Biden said in the video. "There should be no intimidation, no coercion, no threats, no anti-union propaganda. No supervisor should confront employees about their union preferences."

Amazon, America’s second-biggest private employer, has no union labor in the United States, and workers at its fulfillment center in Bessemer, Alabama, would be the first to join if they vote in favor. Such a decision could encourage workers attempting to organize at other Amazon facilities. (Reporting by Julia Harte; editing by Diane Craft)