The Finnish manufacturer has scheduled an event for Monday - the first day of the Barcelona congress - where it is anticipated it will reveal the hotly-anticipated device.
The company has been leaving hints about the phone, the latest being a teaser on its official blog that features four black arrow signs against a green background forming the letter X.
The handset - which is thought to be at the lower end of smartphone pricing - follows Microsoft buying Nokia's struggling mobile business in September in an effort to "accelerate" its challenge to Apple and Google.
According to reports, the X will have an interface that looks more like Windows than Android and feature Microsoft and Nokia services rather than those made by Android-maker Google.
Instead of Google Maps it is expected to have Nokia's mapping service and is not thought to run Google's app store Google Play, instead using a Nokia store with Android apps.
The phone smartphone is expected to have a four-inch screen with a 1GHz dual-core Snapdragon processor, 512MB of memory, 4GB of storage, a microSD card slot and a five-megapixel camera.
It is thought to come in six colour options.
Tom Wiggins, deputy editor of Stuff magazine, said: "The problem with Nokia's most recent phones has never been the hardware, it's the fact that they run Windows Phone, so this could be very good news.
"They've had excellent cameras and often moved away from the black rectangle school of design that most smartphones come from.
"The surprising thing is that Nokia's parent company Microsoft is willing to let it happen, although if you look at how many people are using Windows Phone devices, perhaps it's not such a surprise after all.
"With specs like that it's unlikely to tempt people away from the high-end alternatives offered by Samsung, Apple et al, but perhaps Nokia's just testing the water."
