The Chinese telecoms giant will showcase its Mate 30 range in Munich, Germany, in its first unveiling of an all-new phone since President Donald Trump hit the Shenzhen-based company with an export ban in May.
"The launch will be the most watched ever," said telecoms and media analyst Paolo Pescatore.
"Despite all the concerns surrounding Huawei, and the challenges it faces, it remains defiant and prepared to soldier on."
The No.2 smartphone maker is caught in the fallout of a trade conflict between Washington and Beijing that analysts say is morphing into a technology cold war. It expects the U.S. ban to cost it $10 billion.
Holding the launch in Europe underlines the importance of the region's 500 million consumers to Huawei. It lost five percentage points in market share here following the U.S. ban, even as buyers rallied to its brand at home.
Huawei has been running an online marketing campaign https://consumer.huawei.com/en/campaign/mate30, with the slogan "Rethink Possibilities", recruiting fans to spread the word about the launch. The same website will livestream the event, which starts at 2 pm (1200 GMT).
The build-up has been marked by uncertainty over whether buyers of the flagship Android device will be able to use apps supported by Google.
Google, the unit of Silicon Valley tech giant Alphabet says it won't be possible to sell the Mate 30 with licensed Google apps and services, which include the Play Store or popular tools like Gmail or Maps.
Huawei, for its part, hopes to run the phone on Android 10, the latest version of the operating system, and have access to Google Mobile Services.
Without those, say analysts, consumers won't want the phone - unless Huawei can find a way to convince them that its features are unmatched and its home-grown Harmony operating system is a good-enough fallback option.
Huawei says the phone's 'brain' - the Kirin 990 chipset unveiled at a recent tech fair in Berlin - outperforms the Qualcomm 5G phones already on the market from market leader Samsung.
In particular, the 'big core-tiny core' configuration of the hardware means it can run power-hungry applications like artificial intelligence or support online gaming, while saving battery on routine tasks.
The Mate 30 range's look and feel will be superior to Apple new iPhone 11s, according to analyst Richard Windsor, who said leaked photos showed an attractive circular triple-camera set-up.
"Huawei has Apple soundly beaten when it comes to form factor design but even these beautiful-looking devices are going to struggle to see any volume without the Google ecosystem," Windsor said in a note.
Analysts are keen to learn when the phone will actually ship and how the pricing of the top-end Mate 30 Pro compares with Samsung's Galaxy S10 5G, which retails at $1,299, and the iPhone 11 Pro that starts at $999 but lacks 5G connectivity.
Windsor expects Huawei to offer three further models - the Mate 30, the Mate 30 Lite and a Porsche Design version.
(Reporting by Douglas Busvine; Editing by Elaine Hardcastle)
By Douglas Busvine