It was the Chinese technology giant's most ambitious mobile software push, one it hoped would help its handset business to survive.
A spokesperson confirmed to CNBC that users outside of China would also be able to download it. The company's new foldable Mate X2 device, launched on Monday, would be one of the first to get HarmonyOS with other handsets to follow.
In 2019, Huawei was put on a U.S. blacklist known as the Entity List which restricted American firms from exporting technology to the Chinese company. Google cut ties with Huawei as a result. That meant Huawei could not use licensed Google Android on its smartphones. That's not a big deal in China where Google apps such as Gmail are blocked. But in overseas markets, where Android is the most popular operating system, it was a big blow.