Apple Inc. (AAPL.O) Chief Executive Officer Tim Cook is spending Tuesday with Ivanka Trump touring schools in Idaho, one day after President Donald Trump threatened to slap tariffs on the iPhone and other mobile phones made in China.

Ivanka Trump confirmed the visit in a tweet early Tuesday morning. “Looking forward to visiting the Wilder School District tomorrow with Apple CEO and #STEM education champion Tim Cook!” she said.

The trip provides Cook an opportunity for extended conversation with the president’s daughter and senior adviser just before Trump holds a key meeting with Chinese President Xi Jinping in Buenos Aires later this week. Trade tensions will be a major part of the agenda.

While the iPhone has so far been spared in the U.S.’s ongoing trade war with China, Trump said Monday he may include it in another round of tariffs on Chinese imports. Speaking in an interview with the Wall Street Journal, Trump said he would impose tariffs of either 10 per cent or 25 per cent on remaining Chinese imports if he isn’t able to reach a deal with China.

“Maybe. Maybe. Depends on what the rate is,” the president said, when asked about a potential consumer backlash against tariffs raising the prices of mobile phones and laptops. “I mean, I can make it 10 percent, and people could stand that very easily.”

The iPhone is Apple’s money maker, directly accounting for 63 percent of sales in 2018, and serving as a hub for additional revenues from services and attached devices like the Apple Watch. Alone, it made the company about US$167 billion across the year. Pricing for the newest iPhones ranges from $750 to $1450, while Apple also sells older models starting at US$450 per unit.

Apple shares, which have lost about a fifth of their value in a tech market rout since October, were down 0.4 per cent to US$173.99 at 11:18 am Tuesday morning in New York.

Jessica Ditto, a White House spokeswoman, said Cook and Ivanka Trump’s visit to Idaho on Tuesday had been planned for months.