Apple iPhone 7 retail
Customers wait beside their tents outside an Apple store to buy the newly released Apple iPhone 7 at Kurfuerstendamm boulevard in Berlin, Germany, September 12, 2016. Reuters/Fabrizio Bensch

Even before Apple’s iPhone 7 smartphones hit retail stores Friday, supply of iPhone 7 Plus across the globe has already been depleted, the American tech firm confirmed late Wednesday in California.

Apple Inc. spokesman Trudy Muller confirmed that the first batch of the 5.5-inch iPhone 7 Plus devices in all five colour variants have already been exhausted since the pre-order period commenced Sep. 9. She also admitted that the 4.7-inch iPhone 7 has been sold out in the new Jet Black colour.

"During the online pre-order period, initial quantities of iPhone 7 Plus in all finishes and iPhone 7 in jet black sold out and will not be available for walk-in customers," Muller said in a statement published by TechCrunch.

As such, limited quantities of iPhone 7 in silver, gold, rose gold, and black will be available for walk-in customers starting Sep. 16.

The Apple spokeswoman, however, clarified that customers can continue to order all iPhone 7 models in all colors on

"We sincerely appreciate our customers' patience as we work hard to get the new iPhone into the hands of everyone who wants one as quickly as possible," she added.

High demand for the iPhone 7 Plus could be attributed to the model’s dual-camera design. Unlike the iPhone 7, the iPhone 7 Plus model has two 12-megapixel cameras that employs wide-angle and telephoto lenses for better photo-taking capabilities.

Pre-order of Apple’s iPhone 7 and iPhone 7 Plus devices commenced Sep. 9 in Australia and 28 other countries worldwide. Delivery of the new iOS smartphones are expected Friday alongside the maiden day of retail sale in Apple Stores and Apple resellers worldwide. (Read: iPhone 7, iPhone 7 Plus release date in Australia: Pre-order starts Friday, retail sale follows on Sep. 16)

In Australia, the iPhone 7 costs between $1,079 for the 32GB model to $1,379 for the 256GB variant. On the other hand, the iPhone 7 Plus retails for at least $1,269 for the 32GB model or as much as $1,569 for the 256GB variant.

Customers who don’t want to cash out for the full price have the option to purchase the new Apple smartphones via 24-month plan from various telecom providers. Virgin Mobile has offered the cheapest iPhone 7 and iPhone 7 deals compared to Telstra, Optus or Vodafone. (Read: iPhone 7 price in Australia: Virgin Mobile offers cheapest iPhone 7 postpaid deals)

Owners of previous iPhone models can also trade-up their devices and earn credits towards the purchase of a new water-resistant iOS smartphone. (Read: iPhone 7 price in Australia: Apple Store offers trade-up options)

Demand for Apple’s iPhone 7 and iPhone 7 Plus are expected to increase following the global recall of Samsung’s Galaxy Note 7 devices.