Tim Cook, the company’s C.E.O., said he expected $900 million in extra costs this quarter because of President Trump’s tariffs.

Profit fell 50 percent in the quarter, and the company said one reason was its hiring of additional workers to help its turnaround strategy.

The move comes as President Trump’s tariffs are reducing shipping volumes and is in addition to 12,000 job cuts last year.

The carmaker reported the sharp decline in quarterly earnings after its brand suffered because of its chief executive’s role in the Trump administration.