Apple has revealed its first folding iPhone with a starting price of $2,000 (£1,475).

The new phone, dubbed the Duo, is now one of the most expensive smartphones on the market. The model with the biggest storage option goes up to $3,200 (£2,360).

Chief executive John Ternus said the Duo, which has a book-style format, was “inspired by the iPad” and called the folding features “fluid and completely intuitive”.

But critics say the phone risks becoming a “premium-priced ornament” that doesn’t bring meaningful growth to the firm, which pundits say hasn’t revealed seriously stand-out features in many years.

It comes as John Ternus entered his second week as Apple’s chief executive. Ternus took on the top job after Tim Cook stepped down.

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

When unfolded, it 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.

“The foldable risks becoming a premium-priced ornament in the portfolio, imparting badge value but not meaningful growth,” Dipanjan Chatterjee an analyst at Forrester said.

Chatterjee said the foldable iPhone could go the way of Apple’s Vision Pro headset, which the company priced at $3,699 and has not been a hit with buyers. Or, 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.

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.