WASHINGTON, Dec. 1 (UPI) -- Nintendo says it has increased the production rate of its Wii game console three times this year and still isn't making enough.

"We have worked our absolute hardest to get production as high as possible," said Perrin Kaplan, vice president of marketing at Nintendo of America.

Nintendo has shipped 17.5 million units worldwide since April, Kaplan told The Washington Post. Wii consoles, which cost about $250, went on sale last November and already are sold out in many places this holiday season, the Post reported Saturday.

Wii sales have exceeded those of Microsoft's Xbox 360 console with Sony's latest PlayStation bringing up the rear in sales, the Post reported.

One of Wii's draws is that its users play the system's tennis, golf and boxing games by using hand and arm motions similar to the ones they would use in real games. Other game consoles require players to learn which buttons to push, the Post reported.