However, during President Trump's Gulf tour, he expressed new concern over the supply chain shift (at least for the first time publicly), urging Apple CEO Tim Cook to re-shore some of that iPhone production to the United States. 

"I had a little problem with Tim Cook yesterday," Trump told reporters in Qatar on Thursday, on his latest leg of his Middle East tour. The president said his problem centers around Indian factories producing a "majority" of iPhones for the U.S.

Trump criticized Cook's plan: "I said to him,' My friend, I treated you very well. You're coming here with $500 billion, but now I hear you're building all over India.' I don't want you building in India."

As a result of their meeting, Trump said Apple will be "upping their production in the United States."

Earlier in the week, in the first leg of his tour, Trump praised Nvidia CEO Jensen Huang at the Saudi-U.S. Investment Forum in Riyadh, saying: "Tim Cook isn't here, but you are."

Trump's comments follow a recent Financial Times report indicating that Apple's friend-shoring strategy could result in as many as 60 million iPhones being produced in India by 2026—or the amount required to satisfy the U.S. market.

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Apple does not produce smartphones in North America but has pledged to invest $500 billion in the U.S. market over the next four years.

Wall Street analysts have estimated that U.S. iPhone production would take years and cost tens of billions of dollars.

U.S. Commerce Secretary Howard Lutnick recently spoke with Cook about ramping up iPhone production in the U.S. Cook told Lutnick that "robotic arms" would be needed for production lines. 

Lutnick said, "He's going to build it here," adding, "And Americans are going to be the technicians who drive those factories. They're not going to be the ones screwing it in."

Wedbush Securities recently estimated that a fully American-made iPhone could cost as much as $3,500, compared to the current average price of around $1,000. There are reports the next model could see the first price hike since the 2017 debut of the iPhone X.