The tour was a public symbol of Trump's close relationship with Cook, and also provided an opportunity for the president to showcase a leading American company that's manufacturing in the U.S. as Trump struggles to put into place the first piece of a U.S.-China trade agreement.
"I would always talk about Apple, that I want to see Apple building plants in the United States, and that's what's happening," Trump said in a brief conversation with reporters after the tour. "And Tim Cook is someone I greatly respect."
The relationship between the two men has been cultivated over the past few years through dinners, meetings and Cook's membership on key presidential advisory councils.
Cook and Trump were joined by White House advisor Ivanka Trump and Treasury Secretary Steven Mnuchin, while in Washington, D.C., the House Intelligence Committee continued its impeachment hearings. Trump touched on the hearings in the briefing with the media.
The plant toured on Wednesday, operated by Flex, assembles the Mac Pro, a high-end computer that starts at $6,000. A previous model of the computer was made in the same facility starting in 2013. Apple doesn't own or operate its own manufacturing and instead contracts with companies like Flex. A Flex spokesperson declined to comment.
During the tour, Trump posed with an engraved metal plate reading, "Designed by Apple in California. Assembled in USA," a reference to the Apple slogan that used to be printed on iPhones.
For Apple, the relationship with Trump enables the iPhone maker to communicate at the highest level its position on several trade-related issues, including tariffs. As part of Trump's trade war with China, a 15% import tax will start to affect iPhones in December.
"The nice part here is you don't have to worry about tariffs," Trump said on Wednesday. "When you build in the United States you don't have to worry about tariffs," Trump said. He repeated that he's "looking at" whether to exempt Apple from tariffs on Chinese imports.
Apple doesn't break down its Mac sales by product line, but it's among the company's lowest-volume computers and the only one to be assembled in the U.S. Apple shipped 218 million iPhones in 2018, with the vast majority assembled in China.
The Mac Pro is "an example of American design, American manufacturing, and American ingenuity," Cook said.
In June, Apple announced a new Mac Pro design. The company didn't specify where it would be manufactured, but the Wall Street Journal reported that it would be assembled in China.
Earlier this year, Apple applied for tariff exclusions for 15 parts needed to assemble the computer. When 10 out of the 15 exclusions were granted in September, Apple said it planned to manufacture the Mac Pro in the same facility in Texas that was used for the previous model. The Mac Pro computer will go on sale in December.
"We thank the administration for their support enabling this opportunity," Cook said in a statement at the time.
Apple also announced on Wednesday that it will begin construction on a planned Austin campus that could have the capacity for as many as 15,000 employees.