Nintendo claims that its brand new console, the Wii U, has sold 400,00 units in the United States in its first week of sale. Nintendo of America's president, Reggie Fils-Aime, says the console is now 'essentially sold out' at retailers.

"We are doing our best to continually replenish stock," said Fils-Aime. "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."

Fils-Aime says, however, he doesn't expect stock shortages to reach the levels faced by the Wii on its release in 2006. The original Wii around sold around 475,000 in its first eight days sale in November of that year.

"We've certainly learned many lessons from that and we are replenishing retailers more quickly this time around," he said.

Nintendo has also revealed to CNET that combined with sales of the Wii and the Nintendo 3DS, the company has sold more than 1 million hardware units in the last week. The Wii U is set to go on sale