Apple CEO Tim Cook introduces the iPhone 6s and iPhone 6sPlus during an Apple media event in San Francisco, California, September 9, 2015. [Photo/Agencies]

"Demand is stronger in China than in most regions of the world including the US", said Arik Hesseldahl, senior editor of US tech website Re/code.net, citing the statistics unveiled by an Apple news blog.

The iPhone inventory blog tracks the back-order status of various iPhone models by way of screen shots of Apple's estimated wait times. As of September 12, shipping wait times on the new iPhone 6S Plus in China is running at three to four weeks, and two to three weeks for the 6S.

According to Hesseldahl, one caveat to the data is that there's no indication on how much inventory was allocated by region or carrier. It's also the first day of pre-orders and this data is about as preliminary as you can get.

Apple Inc reported third-quarter earnings in July with revenue in Greater China reaching $13.2 billion, an increase of 112 percent year-over-year, and the sale of iPhones climbing 85 percent.

According to previous reports by China Daily, Apple CEO Tim Cook said that the growth in Greater China was "outstanding" -- the Mac App Store's revenue more than doubled in China and the company intends to open 40 new stores in China by the middle of next year.

"Obviously I can't predict the future, but our performance so far this quarter is reassuring. Additionally, I continue to believe China represents an unprecedented opportunity over the long term," Cook wrote to American news television channel CNBC recently in comments about the company's business in China.

Traditionally, Apple announces its first-weekend sales after a big launch on the following Monday.