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
David Cameron will stand down as Conservative leader ahead of the general election expected in 2020, Iain Duncan Smith said.
Delegates at the SNP spring conference have backed a move to allow all-female shortlists in the Scottish Parliament election next year.
Michael Clarke ended his one-day international career by leading Australia to a simple World Cup final win over New Zealand.