Apple iPhone 6 Review and disadvantages

The result: the iPhone 6 and iPhone 6 Plus may continue to be a tough device to find through the holidays.

While Apple's suppliers have ramped up production of the new iPhones, Cook said the available supply of iPhones isn't even close to meeting customer demand. "We're not even on the same planet," he said on a conference call to discuss the company's fiscal fourth-quarter results.

The comments further illustrate the continued strength of the iPhone franchise, which got a boost after Apple adopted a larger screen size -- 4.7-inch for the iPhone 6 and 5.5-inch for the iPhone 6 Plus -- and introduced new features such as its Apple Pay mobile payment service. The demand has driven Apple to sell 39.3 million units in the fiscal fourth quarter, propelling the company's revenue and earnings past Wall Street expectations.

"We're selling everything we're making," he said.

Cook declined to provide any details on the mix between iPhone 6 and the larger iPhone 6 Plus, noting that it's unfair to look at the mix because everything is selling out. He noted that Apple saw an improvement in demand from every country, which he called unusual.

"It's not a bad problem to have," he said.