Buyers in the U.S. looking forward to purchasing the new 2010 Toyota Prius may have to wait longer than they initially bargained for, following strong demand for the latest hybrid in Japan. Going on sale just a week ago in Japan, the third-generation Prius was a hit before it even descended on showroom floors, with Toyota already sitting on 80,000 advance orders for the car.

Toyota’s original forecast was to sell just 100,000 units of the Prius in Japan for the entire year, but with this goal almost in sight after just a week of sales company execs are now considering reserving more units for Japan at the cost of international markets.

The news comes from Yoshimasa Ishii, Toyota's managing officer for overseas marketing. Speaking with Automotive News, Ishii explained that while Toyota does have an "initial allocation for the United States", very strong demand from Japan may cause the company to "review its sales plan and reallocate the production plan".

Currently, Toyota is hoping to sell around 500,000 units of the Prius globally each year, with the U.S. market expected to absorb around half the sales. If demand in Japan remains high, Toyota may be able to increase production, however, things are not so simple as there are hurdles in terms of battery availability. With this constraint, Toyota may end up limiting the number of cars it sells in certain markets instead.

In the U.S. the new Prius should be arriving within the next month, and if local demand mirrors that of Japan then Toyota will find itself in a strong position next year when it’s scheduled update of its battery plant is complete and production of the Prius can be increased without fear of a lack of supply of batteries.