The new portable video game machine from Nintendo Co. is selling briskly in the United States and Japan, and the company is well on the way to achieving its target of selling 5 million units by April.

The Kyoto-based maker of Super Mario and Pokemon games said Tuesday that U.S. and Japanese sales of the Nintendo DS, which stands for "dual screen" because of its two displays, now total more than a million.

The machine went on sale Nov. 21 in the United States and Dec. 2 in Japan, just in time for the Christmas shopping season. In just five days, 81 percent of the 570,000 hand-helds shipped to Japanese stores had already been sold.

Including advance orders waiting to be picked up at stores, that percentage reaches 90 percent, or more than 510,000, company spokesman Ken Toyoda said. U.S. sales totaled 500,000 in the first week, he said.

Competition over game handhelds is expected to pick up here with the arrival of the first portable from Sony Corp., the electronics and entertainment giant that makes PlayStation 2.

PSP, or PlayStation Portable, is set to hit store shelves in Japan on Sunday. It goes on sale overseas next year.

While being edged out in the home console market by PlayStation, Nintendo has so far dominated the portable market with its Game Boy series.

Nintendo has played down the threat from Sony, saying Nintendo's strength lies in its game software lineup and the ability to make games that are easy and fun. Some say PlayStation games are complex and targeted only at serious gamers.

PSP and Nintendo DS may be going after a slightly different market because some customers are also expected to watch movies on PSP.

Nintendo is sticking to its target of selling 5 million DS machines globally by March 31, the end of the fiscal year, up from its initial forecast of 3.5 million.

"We thought the DS (would) sell well because it got great advance reviews," Toyoda said. "And it's gotten off to a good start."