Rumours continue to swirl around the highly anticipated Apple Car project, with the latest report suggesting the company is close to starting production of the vehicle's battery.

According to the industry news site DigiTimes (via MacRumors), Apple is planning to manufacture batteries for the vehicle in the US rather than overseas. It initially sought a partnership with two of China's largest battery suppliers, CATL and BYD, but negotiations foundered on Apple's insistence that the batteries be manufactured in the US.

Instead, the work is currently expected to be undertaken by Foxconn, already one of Apple's largest suppliers, and Advanced Lithium Electrochemistry. These companies - according to what DigiTimes describes only as "industry sources" - plan to build factories in the US, where they will manufacture the batteries for the Apple Car.

"Semiconductor and lithium batteries are now considered strategic materials by the US government," the site reports. "Although Chinese-made lithium batteries are known for low costs and high performance, with the trade war still raging and the potential of its domestic market, Apple wants to produce its Apple Car batteries at home, the sources said."

None of the companies involved have commented on the report.

Apple has a complex supply chain stretching across numerous countries around the world, but particularly in Asia. (We discuss this in our article Where are Apple products made?) Yet in recent years the company has recognised the political and PR advantages of being seen to make products in its home country, most obviously with the 'Assembled in USA' campaign around the Mac Pro.

Apple's ongoing car project is one of the worst-kept secrets in Silicon Valley. Reports regularly emerge concerning the potential partners with whom Apple is negotiating, but this does not appear to be a straightforward process, particularly when tapping up established car makers; one analyst has described it as a dating game.

You can catch all the latest rumours in our Apple Car news hub.

This article originally appeared on Macworld Sweden. Translation and additional reporting by David Price.