Apple CEO John Ternus told Reuters following the company's earnings report that iPhone Duo supply constraints will persist with no predictable timeline for resolution.

"Duo is constrained as of today," Ternus said. "The ramp is going well, and we're working hard to get it to as many customers as quickly as possible, but at this point, we're not able to predict when supply and demand will be in balance."

Shipping estimates for iPhone Duo orders placed today remain set for late January, with preorders having sold out immediately upon release on October 16. Ternus confirmed that "a very small percentage" of units have been returned due to display issues, and Apple is offering replacements to affected customers.

The iPhone Duo launched last month at $1,999, featuring a 5.4-inch outer display and 7.6-inch inner screen. Preorders sold out immediately, with only limited in-store availability at launch.

Apple reported record quarterly revenue of $114.5 billion, up 12 percent from the year-ago period. Notably, Duo sales were not included in the results as the device did not go on sale until after the quarter ended in September. The company reported record iPhone revenue of $57.58 billion for the fourth quarter.

Ternus also addressed the company's supply chain challenges, citing "unprecedented" memory pricing. He noted Apple expects to see even higher memory costs in the December quarter, though recent price increases provide partial offset. Apple has implemented price increases across its product lineup due to supply chain constraints and rising memory costs.