The world's best-selling hybrid is currently built in Japan and China, but with demand for the efficient cars in the U.S. remaining high, Toyota is reportedly considering adding Prius production to its joint-venture facility operated with General Motors.

The two companies already use the New United Motor Manufacturing, Inc. (NUMMI) factory in California to produce the Toyota Tacoma and Corolla and the Pontiac Vibe. Adding Prius production to the plant would require shipping the parts it can't source in the U.S. - like battery assemblies from its Japanese plants - and assembling them stateside, reports the AFP.

As is its usual policy for major corporate decisions still being negotiated, Toyota has refused to comment on whether it is bringing Prius production to America, but the company did confirm the NUMMI factory was being considered for the project.

Like the company's recent announcement of two new hybrid battery plants in Japan, the addition of more Prius production capacity is aimed at helping the company reach its goal of selling over a million hybrids a year post-2010.