Apple Inc. Chief Executive Tim Cook stood alongside President Donald Trump at the White House today to announce his company will invest an additional $100 billion in its efforts to boost manufacturing in the U.S.

The investment, which brings Apple’s total commitment to $600 billion, will create about 20,000 new jobs for American-based workers at the company, according to the company.

“Today, Apple is announcing it will invest $600 billion in the U.S. over the next four years,” Trump told reporters. “That’s $100 billion more than they were originally going to invest. And this is the largest investment Apple has ever made in America.”

Trump added that the investment marks a “significant step” toward his ambitious goal of ensuring that every iPhone sold in the U.S. is also made in the U.S.

Cook explained that the additional investment will be used to construct a previously announced server manufacturing plant in Houston and fund the development of data centers spread across the country, as well as a new manufacturing academy in Detroit.

According to Cook, the company is also going to launch a new “American Manufacturing Program,” which is focused on bringing as much of the company’s supply chain as possible back to the U.S., including advanced manufacturing operations.

For instance, Apple has committed to eventually manufacturing 100% of the cover glass used on its iPhones and Apple Watch devices at a facility in Kentucky, in partnership with Corning Inc. The company will spend about $2.5 billion on that initiative, Cook said.

“Every new iPhone and every new Apple Watch sold in the world will contain cover glass that’s made in Kentucky,” Cook promised. The company already sources a substantial amount of its cover glass from Corning’s Harrodsburg facility, but it’s not clear when it will be ready to manufacture all of the glass it needs.

The Apple CEO also revealed plans to build an “end-to-end silicon supply chain” in the U.S., which will enable it to increase its chip design, manufacturing and packaging operations in the country.

“American innovation is central to everything we do,” Cook said, adding that his company already “supports 450,000 jobs with suppliers and partners in all 50 states.”

Trump then heaped praise on Apple and Cook especially, calling him a “visionary,” before repeating a threat to slap 100% tariffs on all semiconductors made outside of the U.S if chipmakers don’t strive to manufacture them in the country. “I think the chip companies are all coming back home,” he told reporters. “If you’re building in the United States or committed to build without question, there will be no charge.”

Apple said in February that it’s planning to spend $500 billion over the next four years in an effort to move more of its manufacturing supply chain back to the U.S. As part of that earlier plan, it said it will hire an additional 20,000 U.S.-based workers and build a 250,000 square-foot manufacturing facility in Houston. That plant is set to open in 2026, and will be used to manufacture the servers that power Apple’s cloud-based artificial intelligence services.

The iPhone maker is doing all of this in response to Trump’s threat to impose a tariff of 25% on all handsets made outside of the U.S. The president has previously stated on social media that he wants all iPhones sold in the country to be “manufactured and built in the United States, not India or anyplace else.”

Constellation Research Inc. analyst Holger Mueller said that if anyone is looking for evidence of the success of Trump’s strategy of threatening tariffs, they need look no further than Apple. That said, he conceded that Apple also has business motivations to want to diversify its supply chain, because it has long been overdependent on Chinese suppliers.

“It could be a sign of things to come, if a company with the financial resources and brand status of Apple can be swayed to reflect the administration’s goals,” Mueller said. “Tim Cook may also have been influenced by the fact that a lot of Trump voters have come to resent brands like Tesla, whose owner Elon Musk is now seen as an opponent of the administration.”

However, not everyone was convinced by Cook’s pledge to spend half a trillion dollars on bringing manufacturing back home. Rob Enderle of the Enderle Group told SiliconANGLE that Apple is likely aware of a similar effort by Motorola Inc. several years ago. When that company moved its supply chain back to the U.S., it found that its products were too expensive for the market, and it rapidly lost its status as one of the top U.S. smartphone brands.

“I wonder if this promise, given that it will take longer to implement than Trump’s remaining term, is one that lacks substance,” Enderle said. “Cook may well be trying to manipulate Trump to reduce the tariffs that threaten to damage the smartphone segment so badly.”

There was a small hint that this could be the case. During the press conference, Cook was asked if the company would realistically be able to manufacture an entire iPhone in the U.S. He responded that some components are already made domestically, and that assembly can be done entirely in the U.S., but didn’t make any promises that the entire thing could be manufactured in America. Trump struck a more optimistic tone, saying that a 100% U.S.-made iPhone could well happen “one day.”

Featured photo: The White House/YouTube