Computer chip giant TSMC says it will more than triple its investment in a giant US plant to $40bn (£33bn).
It is one of the largest foreign investments in American history.
The announcement came as President Joe Biden and the Taiwan-based firm's boss opened the factory in Arizona.
The Biden administration is pushing ahead with plans to bring onshore production of key components in everything from phones to military jets.
TSMC is the world's largest maker of micro chips for other companies, with clients including Apple.
Its Arizona plants will produce 3-nm and 4-nm chips used for iPhone processors. Semiconductors are sometimes referred to as the "brains" of electronics like smartphones, car components and AI technology.
Mark Liu, TSMC's chairman, said the firm would build two semiconductor fabrication plants with the first one expected to be online by 2024. The overall investment will be approximately $40bn. It is the largest investment the company has made outside of Taiwan.
The investment is a boost for Mr Biden following supply chain disruption that has led to chip shortages and amid growing tensions between the US and China.
The original deal for TSMC to build a plant in the US came in 2020 when President Donald Trump was in office. The latest announcement vastly increases the size of that investment.
"Today, we're down to producing only around 10 percent of the world's chips, despite leading the world in research and design in new chip technologies," said Mr Biden during a speech in Phoenix on Tuesday.