The next iPhone comes out June 24 in the US and will have a higher-resolution screen, longer battery life and thinner design.
CEO Steve Jobs opened Apple's annual conference for software developers on Monday by revealing the iPhone 4, which will cost US$199 (NZ$299) or US$299 in the US with a two-year contract, depending on the capacity. The iPhone 3GS, which debuted last year, will still be available, for US$99.
It goes on sale June 24 in five countries, expanding to 18 by July and 88 by September in the fastest-ever international roll-out for an iPhone.
In New Zealand, Vodafone will release the new iPhone "in the coming months". No prices or plans have been announced.
The iPhone 4 is about three-eighths of an inch thick; the previous iPhone was nearly half an inch. It is getting a camera on the front that could be used for videoconferencing, in addition to a five-megapixel camera and a flash on the back. It can shoot high-definition video, catching up to some other smart phones.
The display on the new iPhone remains 3.5 inches diagonally, but Jobs said it can show four times as many pixels - the individual coloured dots that make up an image - as the previous screen.
The new phone will run the latest version of Apple's mobile software, now called iOS4, which Apple unveiled in April to offer such new features as the ability to operate more than one programme at a time. Older iPhones will be able to get iOS4 as a download on June 21.
New applications for the device will include the popular game Farmville and one from Netflix that lets people watch streaming video where they left off on a PC.