These new vehicles will help Toyota comply with new rules requiring automakers to ensure that the vehicles they sell in the United States have an average fuel economy of 35 miles per gallon by 2020, he said.
"Toyota strongly supports this long overdue legislation," he said. "We will not wait until the deadline to comply. I have issued a challenge to our engineers to meet the new standards well in advance of 2020. I believe it can be done, it should be done and that Toyota is capable of doing it."
Toyota is also working on developing cleaner and more efficient methods of producing ethanol from wood-waste rather than food crops, he said.
Toyota plans on introducing flex-fuel vehicles capable of running on fuel with up to an 85 percent ethanol content to the US market in 2009.
But there is not sufficient ethanol production capacity for most owners of these vehicles to use the fuel and it is also not yet available in many markets.
Furthermore, the current methods of producing ethanol require large energy inputs and have resulted in sharp increases in corn prices.
General Motors, which currently produces more than a million flex-fuel vehicles a year, also announced plans Sunday to develop more efficient biofuels.
It has partnered with an Illinois-based company, Coskata Inc., which will open a test plant in the fourth quarter of this year capable of producing ethanol from practically any renewable source, including garbage, old tires and plant waste.
Toyota delivered the first two Prius plug-in hybrids in November to universities in California to be tested in real-world conditions, Watanabe said.
It is currently in the planning phase of expanding a battery factory it operates as a joint-venture with Panasonic to build lithium batteries for automotive operations, he added.
A fleet of hundreds of the plug-in hybrids will be delivered to "a wide variety of global commercial customers, with many coming to the United States," he added.