Apple Chief Operating Officer Sabih Khan acknowledged the shipping delays plaguing the new iPhone Duo during the company’s fiscal fourth-quarter earnings call on Monday, but offered little clarity on when customers can expect relief.

The delays were just one point of concern during an earnings call filled with questions about the rising costs memory chip costs, driven by soaring demand from the AI industry.

“iPhone Duo is constrained as of today. The ramp is going well, and we’re working hard to get this revolutionary new product into the hands of our customers as quickly as possible. But at this time, it’s really hard to predict when supply and demand will be in balance,” Khan said.

Customers who didn’t wait in line at an Apple Store or immediately jump on preorders are now seeing ship times stretch into next year. Meanwhile, Verizon has been apologizing to its customers for the delays by offering gift cards.

In an October report from the Financial Times, Apple described demand for the Duo as “nothing short of extraordinary,” after the device sold out on the company’s website within hours of going on sale, pushing delivery dates into next year.

The prolonged shipping delays are notable given Apple’s reputation for its highly efficient supply chain. But the company is hardly alone in facing suply pressures. Soaring demand for memory chips from the AI industry has driven up component costs for hardware makers across the board, dthreatening to push device prices even higher.

Apple, too, has raised prices on a number of products, Khan noted on the call, adding that those decisions were made “reluctantly.”

In another sign of the company’s efforts to meet demand for the Duo, Apple said it’s “deepening” its partnership with Perryman, a titanium producer for supplying materials for the new foldable device.

“We’ve been thrilled with the early response from reviewers and customers, and we are working hard to get iPhone Duo into customers’ hands as quickly as we can,” Apple CEO John Ternus said during his opening remarks.