Nintendo's latest console sells a third less than Wii managed at launch.
Wii U sold 400,000 units during its first week on sale, Nintendo has announced.
The console, which went on sale in North America last Sunday, November 18, was the best-selling Nintendo console throughout Thanksgiving Week. Wii, 3DS and DS each managed to sell through 300,000, 250,000 and 275,000 units respectively within the same time period.
By comparison, Wii sold 600,000 units during its first eight days on sale back in November 2006.
"Wii U is essentially sold out of retail and we are doing our best to continually replenish stock," Nintendo of America boss Reggie Fils-Aime told CNET. "Retailers are also doing their best to get the product to store shelves. But as soon as product hits retail, they're selling out immediately."
Wii U launches in the UK this Friday, November 30.