Apple has described the new iPhone 5S as the "most forward-thinking smartphone in the world".
It is an upgrade to the popular iPhone 5 and features an improved camera and extended battery life as well as novel features like a fingerprint reader.
The introduction of the iPhone 5C marks Apple's first departure from high-end devices.
Chief executive Tim Cook promised the 5C would come with "all the great technology that customers have loved" on its previous models but at around half the price.
More top news
A man caught with dozens of turtles inside his pants is to face a court under the US justice system.
Too many family homes are being built around the size of a bathroom too small for people to live in them comfortably, a report says.
The numbers of female officers in police forces must be boosted further as they tackle the "changing face of crime", Theresa May will say.