Apple Pay activations hit over 1M in first 72 hours, more than all competitors combined

According to Cook, the massive uptake makes Apple Pay the largest contactless payment system in the U.S., more than the combined total of cards registered with competitors.

"The early ramp [of Apple Pay] looks fantastic," Cook said in an interview with WSJ managing editor Gerry Baker.

Cook referred to recent revelations that Merchant Customer Exchange retailers like Rite Aid and CVS are now blocking Apple Pay, characterizing the situation as a "skirmish" that will ultimately be decided by consumers "over the long arc of time."

Apple Pay debuted last week as part of iOS 8.1, enabling the NFC module in the iPhone 6 and iPhone 6 Plus to handle touch-less mobile payments. The payments solution integrates with Touch ID fingerprint recognition, performs tokenized transactions and includes hardware-level data security.