The United Auto Workers is looking to organize workers at Tesla Motors's factory in California, the president of the powerful union said Thursday.

"We're very interested in Tesla," UAW President Dennis Williams told reporters.

"We have contacts there. We know that plant very well," he said, referring to the factory in Fremont, near San Francisco, where the luxury electric automaker builds its Model S and new Model X cars.

Tesla now has about 1,000 employees at the site, the former home of New United Motor Manufacturing Inc., a joint venture between Toyota and General Motors that employed 5,000 UAW members and closed in 2010.

Williams, speaking to reporters at UAW headquarters in Detroit, declined to offer any details of the organizing effort.

But he said he had met in the past with Tesla founder Elon Musk. Musk has said that he would let employees decide if they wanted a union.

"I think he's a fascinating man. When I met him, we had some dialogue," Williams said, adding that Musk had impressed him with his passion for engineering.

Musk also had met with his predecessor, former UAW president Bob King, Williams  noted.

Williams pointed out that Tesla was still producing a relatively small number of vehicles but has plans to build as many as 500,000 electric vehicles annually by 2018.

"We're not approaching this in adversarial way. We recognize that Tesla is a start-up," he said. "We just think people have the right to belong to a union."

Williams added that healthy unions are critical to building a strong middle class both in the United States as well as in countries such as Mexico, where he said government and corporate interests have combined to keeps wages low.

"I am interested in helping workers in Mexico. Mexico would be a great trading partner if they had free unions and the ability to raise wages," he said.

The UAW president also said he hopes to launch a fight in the US that would limit corporate use of temporary workers, saying it leads to worker abuse.

Williams cited Japanese automaker Nissan as among the companies hiring hundreds of temporary workers to staff US factories to avoid paying higher wages or benefits such as health insurance.

"Nissan has all these temporary workers. They have no employment rights. To me that's abuse. That's so immoral," he said.