Sales of Apple's first folding phone, the iPhone Duo, began on Friday, with market watchers betting on whether the device can reinvent the small foldables market in the same way the iPhone did for smartphones. The Duo's reception could prove an early test for new chief executive John Ternus, the former hardware chief who unveiled the phone barely a week after taking charge in September. It could also have large implications for a niche category in which ⁠rivals such as Samsung Electronics and Huawei Technologies have sold premium offerings for several years. Within minutes of pre-orders opening last Friday, Apple's estimated delivery dates for the Duo had slipped to late January as demand outpaced supply. The US company called the response from customers "nothing short of extraordinary". In Sydney, the first Apple store to sell the phones on Friday, a queue of customers formed outside before it opened at 8am. Simon Krishnan, a 48-year-old engineer, paid A$3,899 for a Duo with 512GB memory. "This is a bit of a luxury item for me, because it's so expensive, but I just think, you know what? Life's too short," he said. In China, a soft consumer market combined with memory costs pushing prices higher has led to six straight quarters of declines in smartphone shipments. Apple's market share, however, has rebounded as some phone buyers trade up to premium devices while others seek value at the lower end of the market, putting pressure on mid-range brands. Liu Wei, a 26-year-old healthcare professional, already has a foldable phone from Xiaomi, but still queued outside a central Shanghai Apple store from 6am to get his hands on Apple's first foldable. "I've used Apple products for many years and I have more trust [in the brand], so I bought one on launch day to try it out," he said. In Hong Kong, May, 38, secured a 256GB iPhone Duo, which retails for HK$17,499, during an online pre-sale and aimed to resell the handset for a profit of around HK$4,000: “A few meals' worth of money,” he joked. The limited supplies could disappoint Apple fans lining up in front of stores to buy the Duo. Apple has said walk-in availability would vary by jurisdictions and, with limited stocks in the US, Australia, Canada, Mexico and much of Britain and Europe. In Hong Kong, the Chinese mainland, France, India and Japan, units would be available only for customers who had ordered online. (Reuters) Edited by Aaron Tam

Al Jazeera interviews Fatih Birol in Berlin as the Iran war disrupts global energy supplies.