Nintendo's latest console shifted approximately 57,000 units in North America during January and roughly 64,000 units in February, according to the latest NPD figures (via Gamasutra).
In comparison, the Xbox 360 is believed to have sold 302,000 units in the last month, outperforming the Wii U by a ratio of almost 5:1.
The Wii U's poor performance in January was blamed by a surge in second-hand console sales after Christmas.
Nintendo previously lowered its Wii U sales forecast after lower-than-expected festive sales.
The firm cut the number of anticipated Wii U console sales from 5.5 million units to 4 million units by the end of the financial year.
Meanwhile, retailers including Amazon and Asda have recently lowered the price of the Wii U to under £200.
Upcoming Wii U titles include Monster Hunter 3: Ultimate, LEGO City Undercover and an HD Wind Waker remake which will be released later in the year.
Nintendo recently confirmed that both a new Mario Kart and a 3D Super Mario are also in development and will be shown at the E3 Gaming Expo.
Watch a trailer for upcoming Wii U game LEGO City Undercover below: