Apple Inc. (AAPL.O) said it would invest $1 billion to expand its operations in Austin by constructing a new employee campus in the area, large enough to house 15,000 additional employees.

Further facilities will also be established in Culver City, Seattle and San Diego, and existing sites in Pittsburgh and Boulder will be expanded over the next three years. In a statement on its website Thursday, the company said it was also considering other U.S. regions for growth.

"With this new expansion, we’re redoubling our commitment to cultivating the high-tech sector and workforce nationwide,” Apple Chief Executive Officer Tim Cook said in the statement. Apple shares rose less than 1 per cent to US$170.29 this morning in New York.

The company said the second Austin building would cater to a wide range of business disciplines, including R&D, sales, customer support, and engineering.

Austin is already the largest home for Apple employees after the iPhone-maker’s Cupertino headquarters, with about 6,200 people working at the existing site about a mile from the location of the new facility.

The investment will follow announcements from other major tech companies, which have been laying out their U.S. expansion plans. E-commerce giant Amazon Inc. recently revealed plans to build a major new campus in New York, while Google has opened new offices in sites including Boulder, Colorado.

Among U.S. President Donald Trump’s “America First” policies were promises to bring manufacturing jobs back to the U.S. from Asia, and businesses have been increasing efforts to hire locally to avoid conflict.

Apple has long used China as its production base for everything from the signature iPhone to iPads and Macs. In his early years running Apple, Cook responded to questions about increasing manufacturing in the U.S. by saying the skill sets in China are more conducive to producing the company’s products.

However, in recent months, Cook has modified that view, saying in an interview this year that “it’s not true that the iPhone is not made in the United States.” Some components, like the smartphone’s glass cover, are manufactured in the U.S. and shipped for assembly in China.

In December 2013, Cook said on Twitter that the then-flagship Mac Pro desktop computer would be manufactured in Austin, rather than China.