Intel chief executive Brian Krzanich used a surprise Oval Office visit Wednesday to announce a $7 billion investment in an Arizona computer chip factory that has sat empty since construction wrapped up three years ago.

The chipmaker said the factory, called Fab 42, will employ 3,000 when it opens in 2020 or 2021 - a decade after construction began and several years behind schedule. The Chandler, Arizona, plant will make chips using technology developed at Intel's new D1X research factory in Hillsboro.

Wednesday's announcement represents a windfall of publicity for Intel and for President Donald Trump, who has been advocating new policies to boost domestic manufacturing and has touted a series of manufacturing investments from Ford Motor Co., air conditioner manufacturer Carrier and others since his election in November.

"This factory will help the U.S. maintain its position as the global leader in the semiconductor industry," Krzanich said in a written statement.

"We're very happy, and I can tell you the people of Arizona are very happy," Trump declared.

However, chip industry analyst Jim McGregor said the changing political climate in Washington had nothing at all to do with Intel's decision to finally move ahead with the idle factory in Arizona.

"Intel's fab strategy has been set for at least a decade," said McGregor, who works with TIRIAS Research in Arizona.

Intel indicated that the new factory will make its forthcoming 7 nanometer microprocessor technology, two generations ahead of Intel's current processors.

The timing of the Fab 42 opening means Intel will almost certainly develop that new technology in Hillsboro, where it has crafted each of its last several generations of processors.

This is actually the second time an Intel chief stood next to a president and announced this factory. In 2011, former CEO Paul Otellini welcomed President Barack Obama to Hillsboro and promised a hiring and spending spree, including a $5 billion investment for the Arizona facility.

Wednesday's announcement suggests Intel is finally making progress in deploying a new production technology, called extreme ultraviolet (EUV), which will enable smaller features on its microprocessors.

That's a positive signal for Intel's operations in Oregon. The chipmaker built both Fab 42 and its new D1X research factory in Hillsboro to accommodate the enormous EUV manufacturing tools.

Intel mothballed Fab 42 in 2014, in part, because it didn't need more production capacity as sales ebbed, and also because the EUV manufacturing technology wasn't ready for mass production.

Recent signals suggest EUV is now close, making the new factory in Arizona and D1X in Oregon indispensable for Intel.

Fab 42's arrival could mean changes at the chipmaker's other sites, though.

"Although that's big news, I would expect you're going to see the closure of older fabs," McGregor said.

The aging Fab 11x in New Mexico is in particular jeopardy; it has been several years since Intel upgraded it for contemporary manufacturing technologies. McGregor said the 15-year-old Fab 22 in Arizona could also close, at least temporarily, for a retrofit as Fab 42 comes online.

"I wouldn't look at this as creating new jobs," McGregor said. "It's most likely the reshuffling of resources. Obviously the PC market isn't picking up."

Intel eliminated 15,000 jobs last year to prepare for a long-term decline in the PC industry but ultimately posted strong financial results, buoyed by its robust data center business.

For 2017, though, Intel forecasts very modest growth, and the company indicated last month that its expectations for the PC market are even worse than outside analysts' dismal forecasts.

Still, other parts of Intel's business are expanding. And McGregor said it is possible Intel might be quietly preparing to buy other semiconductor companies, which would require more manufacturing capacity.

Intel's shares were up 7 cents Wednesday morning, at $36.41. The company's stock is near a multiyear high.

Krzanich was among the tech executives courting Trump during the presidential transition. He attended a summit at Trump Tower in New York and later joined the administration's new American Manufacturing Jobs Initiative.

However, last week Krzanich denounced Trump's ban on immigrants from seven predominantly Muslim countries. And over the weekend Intel joined other tech companies that filed legal briefs opposing the executive order.

In January, Krzanich said he had advised Trump against protectionist trade policies the new president has sometimes advocated.

Unlike many large tech companies, Intel makes most of its technology in the United States. Krzanich said Wednesday that Intel sells 80 percent of its products overseas.

Intel is one of the largest users of H-1B visas, which allow highly skilled workers from other countries to work in the U.S. Trump has suggested he may seek major changes to the program, though substantial reform would require congressional action.

"When we disagree, we don't walk away," Krzanich said in a letter to employees Wednesday. "We believe that we must be part of the conversation to voice our views on key issues such as immigration, H1-B visas and other policies that are essential to innovation.

After his appearance at the White House, Krzanich is due back at corporate headquarters in California early Thursday morning for Intel's annual investor day.

-- Mike Rogoway; twitter: @rogoway; 503-294-7699