Technology giant Apple has unveiled new iPhones, including one that is its largest and the most expensive one, and the products will be available in India next month.

In one of the company's signature launch events at its headquarters in Cupertino, California Wednesday, Apple CEO Tim Cook unveiled the iPhone Xs and iPhone Xs Max, the most advanced iPhones ever.

The 5.8-inch iPhone Xs and 6.5-inch iPhone Xs Max feature Super Retina displays, a faster and improved dual camera system, the first 7-nanometer chip in a smartphone among other features. The company said the new iPhones would start at USD 750, USD 1,000 and USD 1,100. Last year, the starting prices were USD 700, USD 800 and USD 1,000.

IPhone Xs and iPhone Xs Max will be available for pre-order beginning Friday, September 14 and in stores beginning Friday, September 21.

"iPhone Xs is packed with next-generation technologies and is a huge step forward for the future of the smartphone," Apple's senior vice president of Worldwide Marketing Philip Schiller said.

He said iPhone Xs is not one, but two new iPhone models, and iPhone Xs Max offers the biggest display ever in an iPhone with the biggest battery ever in an iPhone, delivering up to an hour and a half more battery life.

IPhone XR will be available in 64GB, 128GB and 256GB models in white, black, blue, yellow, coral and red starting at Rs 76,900 through Apple authorised resellers. Customers will be able to pre-order iPhone XR beginning October 19 with availability beginning October 26 in more than 50 countries and territories including Australia, Canada, China, France, Germany, India, New Zealand and US.

IPhone Xs and iPhone Xs Max build on the all-screen design of iPhone X and feature the sharpest displays with the highest pixel density of any Apple device, the company said. IPhone Xs and iPhone Xs Max come with iOS 12, the world's most advanced mobile operating system.

Apple also introduced the Apple Watch Series 4, redesigned and re-engineered to help users stay connected, be more active and manage their health in new ways. While retaining the original iconic design, the fourth-generation Apple Watch has been refined, combining new hardware and software enhancements into a unified form.

The Series 4 watch with watchOS 5 includes revolutionary health capabilities, including a new accelerometer and gyroscope, which are able to detect hard falls, and an electrical heart rate sensor that can take an electrocardiogram (ECG) using the new ECG app, which has been granted a classification by the US federal agency Food and Drug Administration (FDA).

"The completely redesigned Apple Watch Series 4 continues to be an indispensable communication and fitness companion, and now with the addition of groundbreaking features, like fall detection and the first-ever ECG app offered directly to consumers, it also becomes an intelligent guardian for your health," Apple's chief operating officer Jeff Williams said.

Beginning September 14, Apple Watch Series 4 (GPS) will be available to order in 26 countries and territories and Apple Watch Series 4 (GPS + Cellular) will be available to order in 16 countries and territories. Both models will be available in stores beginning September 21.

Apple explained that the Series 4 watch enables customers to take an ECG reading right from the wrist using the new ECG app, which takes advantage of the electrodes built into the Digital Crown and new electrical heart rate sensor in the back crystal.

With the app, users touch the Digital Crown and after 30 seconds, receive a heart rhythm classification. It can classify if the heart is beating in a normal pattern or whether there are signs of Atrial Fibrillation (AFib), a heart condition that could lead to major health complications. All recordings, their associated classifications and any noted symptoms are stored in the Health app in a PDF that can be shared with physicians, Apple said.