Mr Cook, speaking at the first event at the new campus theatre named for the late Apple co-founder Steve Jobs, said the latest flagship handset is a milestone for the company a decade after the first iPhone release.
It's expected a product to mark 10 years since the first iPhone will be announced at the event.
The successors to iPhone 7 and iPhone 7 Plus run on the new A11 Bionic chip that the company says has two performance cores (25 percent than last year's A10), and four high-efficiency cores (70 percent faster than A10).
Ahead of the much-awaited launch, there has been a major leak of features, including the anticipated name of Apple's latest iPhone.
In touting new health capabilities for the Apple Watch, Apple sounded a lot like Fitbit. The iPhone X 64GB is likely to cost $999, the iPhone 256GB will cost $1099 while the most expensive variant with price of $1199 could be the iPhone X 512GB.
Apple also introduced an upgraded version of the Apple TV capable of handling 4K video and equipped with special colour-enhancement technology.
The iPhone 8 or iPhone X, will be available for pre-order on September 15 and will hopefully hit the Apple store shelves on Friday, September 22.
You can also watch the Apple Event livestream here. The Apple Watch is just as impressive.
IHS Markit said India is an interesting market, and one where Apple is looking to grow, in part through domestic production.
And they're not actually saying "X" they're calling it iPhone 10 - you don't pronounce the Roman numeral.
Kiwis will still be able to buy the non-cellular version of the Apple Watch Series 3.
Just how much are you willing to pay for the new iPhone?
"Unlike the early days of the Apple iPhone, all the operators carry iPhone 8 so a launch does not give competitive advantage to those that have the iPhone versus those that do not", said Ian Fogg, senior director, mobile & telecom at IHS Markit.
The only people who know today what the new iPhone models are, what they look and feel like and their pricing will be the three telcos, Singtel, StarHub and M1 and the Apple Orchard Road store. The original Series 1, without Global Positioning System, sells for $249, down from $269. One of the most notable changes is that Apple is expected to ditch the home button on the device.
Going by Apple's traditional iPhone release formula, the brand spanking new iPhones should go on sale a week after the model has been revealed to us. It may also include facial recognition technology for unlocking the phone and wireless charging.
Cellular version is $399, $329 for WiFi only. In India, the phone is expected to come before Diwali, although rumours have already started floating that it may even come in the month of September itself.