Chinese tech giant Huawei on Tuesday unveiled its first smartphone equipped with a fully homegrown operating system, a key test in the firm's fight to challenge the dominance of Western juggernauts.

Apple's iOS and Google's Android are currently used in the vast majority of mobile phones, but Huawei is looking to change that with its newest Mate 70 devices, which run on the company's own HarmonyOS Next.

The launch caps a major turnaround in the fortunes of Huawei, which saw its wings clipped by gruelling US sanctions in recent years but has since bounced back with soaring sales.

"Today, the long-awaited Mate 70, the most powerful one ever, is here," Richard Yu, chairman of Huawei's Consumer Business Group, told a raucous launch event Tuesday at the firm's Shenzhen headquarters.

The risks are high -- unlike a previous iteration, based on Android's open-source code, HarmonyOS Next requires a complete rewiring of all apps on the smartphones it powers.

"HarmonyOS Next is the first home-grown operating system, a milestone for China to move away from reliance on Western technologies for software with performance improvement," Gary Ng, a senior economist at Natixis, told AFP.

More than three million have been pre-ordered, according to Huawei's online shopping platform, though that does not require them to be purchased.

It went on sale just after 6:00 pm (1000 GMT) on Tuesday.

Around 100 people queued outside a Huawei store in central Beijing an hour before orders opened.

- 'Innovate on our own' -

Second in line was 28-year-old Zhang Nannan, who switched to a Huawei phone from Apple last year.

Huawei phones take clearer photos and get better signal, he said, while "supporting domestic products" was another draw.

"We must innovate on our own, and cannot let ourselves be disrupted by foreign countries," he said.

Huawei was once China's largest domestic smartphone maker before it became embroiled in a tech war between Washington and Beijing.

The company shipped more than 10.8 million smartphones in the third quarter -- capturing just 16 percent of the Chinese market, according to a recent report by technology research firm Canalys.

In September the firm unveiled the world's first triple-folding phone, the Mate XT, priced at an eye-watering $2,800 which made it three times the cost of the newest iPhone.

The Mate 70 has a much lower starting price of $758, the firm announced Tuesday.

Those who purchase a Mate 70 smartphone will be given the choice to opt out of the fully self-developed operating system, the firm said.

Yu said that there are "many application updates" taking place on a daily basis.

"We expect that in two or three months, the application user experience of our HarmonyOS ecosystem will be more mature and more perfect," he added.

- 'High expectations' -

Huawei found itself at the centre of an intense tech rivalry between Beijing and Washington, with US officials warning its equipment could be used to spy on behalf of Chinese authorities -- allegations they deny.

Since 2019, US sanctions have cut Huawei off from global supply chains for technology and US-made components, a move that initially hammered its production of smartphones.

That is only set to intensify under US President-elect Donald Trump, who has promised huge tariffs on Chinese imports in response to what he says are Beijing's unfair trade practices.

"Rather than Huawei inspiring the tech industry as a whole, it is the self-reliance trend of the Chinese tech industry that has made Huawei's progress possible," Toby Zhu, a senior analyst at Canalys.

The success of Huawei's new generation of smartphone products will be a key gauge of whether that drive has worked, said Zhu.

"This generation of products cannot afford to miss the mark because everyone has high expectations for them," he added.

But it is unclear whether developers overseas will be willing to spend the money needed to build a completely new version of their apps for the latest smartphones, said Rich Bishop, co-founder and CEO of AppInChina, a publisher of international software in China.

One third-party agency in China quoted a price of two million yuan ($275,500) to custom-fit a foreign app for HarmonyOS Next.

To convince them, "Huawei needs to continuously improve the software, provide better support for developers, and convince the developer community that it is committed to the long-term development of the Harmony ecosystem", Paul Triolo, a partner at consulting firm Albright Stonebridge Group,