Apple is spending a lot on President Donald Trump’s tariffs. During an earnings call on Thursday, Apple CEO Tim Cook said the duties could add $1.1 billion to its costs during the September quarter.

Cook says Apple has already spent around $800 million during the June quarter, which is less than the $900 million that the company predicted in May. “The bulk of the tariffs that we paid were the IEEPA [International Emergency Economic Powers Act] tariffs that hit early in the year, related to China,” Cook said.

Trump’s sweeping tariffs have impacted all of Apple’s devices, which are mainly manufactured in China, India, and Vietnam. Cook said the “majority” of iPhones sold in the US are manufactured in India, while most Macs, iPads, and Apple Watches come from Vietnam. Trump has threatened to target Apple with even higher tariffs if the company doesn’t move some of its production to the US.

“There are many factors that could change, including tariff rates,” Cook notes. Despite concerns surrounding tariffs, the company’s quarterly revenue jumped 10 percent to $94 billion between April and June, while iPhone and Mac sales remain strong.