The Galaxy Z TriFold will go on sale on December 12 and costs more than twice as much as the new iPhone 17 at $2,443.

Super thin, it unfolds to a 10-inch (25.4 centimetre) display, offering "increased possibilities for creating and working", the South Korean tech giant said.

The triple fold function is not world-first -- China's Huawei beat Samsung to the punch last year with a phone at a similarly exorbitant price.

Growth has been patchy in the competitive smartphone market, pushing makers to find new, eye-catching ways to differentiate their products.

Offered solely in a black design, Samsung's new device comes in at 309 grams (10.9 ounces) and at its thinnest point measures less than 0.2 inches.

Generative artificial intelligence features are integrated into the phone, which can give real-time help through screen or camera sharing.

Samsung admitted the Galaxy Z TriFold was "not intended for mass sales".

Kim Seong-eun, Executive Vice President at Samsung Electronics said it was a "special edition" product.

The launch comes as recent industry numbers suggest Apple is on track to overtake Samsung for the first time in 14 years as the world's top smartphone maker through 2029.

Apple has also long been rumored to be planning a foldable iPhone, possibly as early as next year.

The US company's smartphone shipments are expected to reach a global share of 19.4 percent in 2025 while Samsung is expected to hold 18.7 percent -- with Apple effectively dethroning its rival for the first time, according to research firm Counterpoint.