Nintendo president Satoru Iwata has given his first public thoughts on the sales of Wii U, saying that the new console is selling "steadily" after it released worldwide in November/December.

Speaking to Reuters, Iwata said the clear difference between Wii U's launch and that of Wii in 2006 was that the preceding console enjoyed mass sell-outs long into its lifetime.

"At the end of the Christmas season, it wasn't as though stores in the U.S. had no Wii U left in stock, as it was when Wii was first sold in that popular boom. But sales are not bad, and I feel it's selling steadily."

Iwata also pointed out the challenge of launching two different SKUs of the console - a first for Nintendo.

"It was the first time Nintendo released two models of the game console at the same time ... and I believe there was a challenge with balancing this. Specifically, inventory levels for the premium, deluxe package was unbalanced as many people wanted that version and couldn't find it."

The latest weekly charts from Japan have been delayed by Media Create due to the holiday period, but it is believed Wii U has sold about 640,000 units in Japan by the post-Christmas week, having launched on December 8th