John Ternus has entered his second week as Apple's chief executive and the company has revealed the first major change to the iPhone since it was released almost 20 years ago.

Ternus, who took on Apple's top job after Tim Cook stepped down, was onstage on Wednesday at the company's annual product release event in front of huge images of the first foldable iPhone.

With a book-style format, the new iPhone, dubbed the Duo, is the largest ever size of the product. And with a starting price of $2,000 (£1,475) going up to $3,200, it is also the most expensive. UK prices start at £1,999.

Ternus said the Duo was "inspired by the iPad" but called the folding features "fluid and completely intuitive."

The foldable phone has been a work-in-progress inside Apple for several years.

When unfolded, the new Duo has the look of a small iPad. When folded in half, it has the look of a wider iPhone.

Ternus said during the event that Apple wanted to avoid the look and feel of other foldable smart phones on the market, which he said "feel like two phones stuck together... making a larger screen feel much smaller."

The Duo, he said, is the "result of a series of remarkable innovations that we think will redefine the experience of using a foldable phone."

Ternus was directly involved in developing the foldable iPhone as he spent many years as a top executive inside Apple's hardware division before being tapped earlier this year as Cook's successor.

Ben Wood, chief analyst at technology research firm FDM, said it was likely Ternus's promotion was timed specifically "to coincide with what will be arguably one of the biggest iPhone launches for many years".

"Nothing happens by accident at Apple," Wood added.

Altering the design of the iPhone may address some criticism that Apple has yet to land a major product hit or truly exciting innovation since the first iPhone came out in 2007.

Previously, the highest starting price of the newest iPhone was $900 (£664). Apple also revealed on Wednesday the new iPhone 18 and 18 Pro, which start at $1,200 (£885) and $1,300 (£959) respectively.

Chatterjee said the foldable iPhone could go the way of Apple's Vision Pro headset, which the company priced at $3,699 (£2,729) and has not been a hit with buyers. Or, he said, it could be the company's next Apple Watch which, while not as popular as the iPhone, is bought by millions of people each year.

The way people have become accustomed to the way the iPhone operates is another potential hurdle to Apple seeing big sales of the new design.

"Foldables are interesting devices", Milanesi noted. "A lot of people are intrigued by it, but the software and the learning curve that you have from moving from a traditional phone to a foldable is real."

Wood noted that the current market for foldable smartphones from the likes of Samsung and Huawei make up only 2% of smartphone sales. Even with Apple's version likely driving interest and demand, sales are only expected to reach 4% of the total market in the next decade, according to data and analytics firm FDM.

The iPhone has been Apple's top-selling product and accounts for more than half of the company's sales each year.

In recent quarters, the company has boasted that the iPhone is more in-demand than ever, with the most recent version of the device becoming its most successful product launch.

Starting with the iPhone 18, the bot will now be able to go across information on a person's phone, like messages and emails, to find information, answer queries and take action on a person's behalf.

Some Siri AI features will also be available on the new Apple Watch, including the ability to take notes of conversations and transcribe them, should a wearer enable that feature.

Ternus referred to new AI-enabled capabilities on the iPhone as an "intelligent personal hub", and admitted that Apple would be making use of "the most private details of your daily life."

He insisted that all of it will remain private, with the AI features often running "on device", meaning not through third-party companies. And when a third-party is required for a function, Ternus said it will remain private in a remote server, or cloud.

"Others see that data as something to collect and store", Ternus said. "Here, not even Apple can access what's yours."