JACKSON, Miss. (AP) — Nissan Motor Co. is declining to talk to union supporters about conditions at its Mississippi assembly plant.

A March 14 letter from Nissan executive Scott Becker to the United Auto Workers union declines to address demands presented after a March 4 pro-union rally.

Becker describes claims that Nissan is improperly intimidating pro-union workers as "categorically false."

He says that it's up to employees at the 6,400-worker to decide whether they want a union or not. Nissan management opposes unionization in Canton, Mississippi.

U.S. Sen Bernie Sanders and NAACP President Cornell William Brooks were among those who spoke at the rally. They asked Nissan to discuss a neutrality agreement with the UAW.

Brooks says he's disappointed that Nissan responded only to the UAW and says the company should discuss the issue.