Japanese automaker Honda has begun commercial production of its zero-emission vehicle powered by a hydrogen fuel-cell engine.

The four-seater FCX Clarity runs on both hydrogen and electricity and emits only water vapor, the company said.

"This is indeed a historic day for both Honda and American Honda -- a new chapter in our nearly 50-year history in America," said John Mendel, executive vice president of America Honda Motor Co. "It's an especially significant day for American Honda as we plant firm footsteps toward the mainstreaming of fuel-cell cars."

Honda, Japan's second-largest automaker, says the car is two times more energy-efficient than a gas-electric hybrid and three times that of a traditional, gasoline-powered car.

The automaker is to produce 200 of the vehicles over the next three years.

Demand for fuel-efficient vehicles has been growing steadily amid concerns over global warming and soaring gas prices at the pumps.

But analysts say the cost associated with fuel-cell vehicles and the dearth of hydrogen fueling stations, in particular across the US, are major obstacles preventing wider adoption of fuel-cell cars by consumers.

MK/MR/GM