Toyota said domestic production fell in July, outweighing record overseas production that was driven by a strong recovery in Europe, China and the rest of Asia.
China is Porsche biggest single market with sales up 8 percent in 2021.
Toyota's global production plan for June stands at about 850,000 vehicles, a cut of about 100,000 vehicles.
Toyota said there was "a possibility" that it could lower its full-year production plan of 9.7 million vehicles as it faces a continuing shortage of parts due to the COVID-19 lockdowns in China.
Mercedes, which did not disclose the location of Envision's new U.S. cell factory, also flipped the switch on a new battery assembly plant located on 270 acres near its vehicle factory.
The expansion, if it goes ahead, would give Tesla EV-dedicated production capacity in the world's largest auto market on a par with more established brands in China.
Toyota's new EV will be slightly bigger than its compact Corolla, the world's best-selling car of all time. One source told Reuters that the vehicle is like a "Corolla with bigger back-seat section."