CVS and Rite Aid – two major drug store chains in the US – have stopped accepting payments via Apple Pay, which allows contactless payments via NFC and was launched just last week, said Macrumours. Both are members of Merchant Customer Exchange (MCX), which is developing its own mobile wallet called CurrentC.

MCX was created by big retail brands including Walmart and Best Buy, and it was earlier reported that they too had stopped accepting Apple Pay.

At the Wall Street Journal Digital Live conference, Apple CEO Tim Cook responded to the move by saying that “We’ve got a lot more merchants to sign up, we’ve got a lot of banks to sign up and we’ve got the rest of the world.”

“It’s a skirmish… Merchants have different objectives sometimes. But in the long arc of time, you only are relevant as a retailer or merchant if your customers love you,” he added.

CurrentC is as an app that lets customers pay in-store, as well as save and earn participating merchant loyalty rewards.

“Apple Pay, I believe, was viewed as a threat and therefore — even though they supported Google Wallet — they seemed to back away from it and not support it, and cut off consumers from their ability to transact,” said Patrick Moorhead of Moor Insights & Strategy, speaking to Re/code.

CurrentC plans to launch next year and will be accepted at 110,000 locations in the US, with Apple Pay and Google Wallet as its main rivals.

However, unlike Apple Pay, which lets customers use their traditional credit card accounts, CurrentC will require users to connect their bank account to the app or get a retailer’s branded debit or credit card.

While MCX is supported by big chains like Dunkin’ Donuts, GAP and 7-Eleven, Apple Pay has American Express, MasterCard and Visa in its corner with organisations like Arbnb, Disney Store and Eventbrite set to come on board by the end of the year. Touch ID is used to authorise in-app payment with Apple Pay and with a straightforward sign-up and positive reviews, it has been doing well.

Given the uncertainty on whether all its backers will introduce CurrentC, it is still unclear if it will pose a formidable threat to Apple Pay.