Back in May 2020 TSMC, the world’s largest contract chipmaker, announced it would build a $12 billion factory in Arizona, an apparent win by the Trump administration in its push to wrestle global tech supply chains back from China.

TSMC is setting up a 12-inch wafer fabrication plant in Phoenix, and the facility is expected to start volume production in 2024, Taiwan’s investment commission of the ministry of economic affairs, which approved the investment, said in December.

TSMC manufactures the bulk of its chips in Taiwan and has older chip facilities in China and the U.S. state of Washington.

Three sources familiar with the matter, speaking on condition of anonymity as they were not authorized to speak to the media, told Reuters that up to five additional fabs for Arizona are being planned.

The initial fab is relatively modest by industry standards, with a planned output of 20,000 wafers - each of which contains thousands of chips - every month using the company’s most sophisticated 5 nanometer semiconductor manufacturing technology.

It is not clear how much additional production capacity and investment the additional fabs might represent, and which chip manufacturing technology they would use.

TSMC last month said it planned to invest $100 billion over the next three years to increase production capacity, though it did not give details.

One person with direct knowledge of the matter told Reuters the expansion was in response to a request from the U.S., but declined to provide further details.

The source added that "The United States requested it. Internally TSMC is planning to build up to six fabs," though it was not possible to provide a timeframe. For more, read the full Reuters report.

Whether any of the new plants are planned to support Apple chips in the future is unknown at this time.