Providence — Rhode Island is offering $2,500 rebates to encourage residents to buy or lease plug-in cars, joining a growing number of states inviting drivers to go electric.

Only about 450 electric-powered vehicles are on the roads of the nation's smallest state, far fewer than in neighboring Massachusetts — where nearly 5,500 are registered — or Connecticut, which has about 1,400.

"We're a little behind some of our fellow New England states that have been national leaders," said Rhode Island Energy Commissioner Marion Gold.

She announced the new incentives Friday at the opening of the Northeast International Auto Show in Providence.

The moves by states to build consumer momentum for electric cars aim to reduce air pollution from gas-powered vehicles.

The rebates also are seen as a popular measure to help people save on fuel.

A $200,000 pool of state money will cover an estimated 80 to 100 new vehicles.

"We figured we had to get started," said Gold, who hopes to expand the pilot if the rebates run out and new sources of money are found. "It's a great push. It's like a big giant coupon."

The biggest rebates go to cars with the highest battery capacity. Amounts range from $500 toward the purchase of a plug-in Toyota Prius to the maximum $2,500 for about 10 different vehicles, from Tesla models to the Nissan Leaf or the BMW i3.

Nearly 40 states now offer some kind of incentive to replace gasoline-powered cars with electric models, according to the National Conference of State Legislatures.

Those range from financial incentives such as rebates and credits to special parking privileges, exemptions from emissions tests or the ability to drive on freeway fast lanes.

Rhode Island's new program is comparable to the rebates now offered in neighboring Connecticut and Massachusetts, said Democratic U.S. Sen. Sheldon Whitehouse, who also spoke at the car show Friday.

The maximum rebate in Massachusetts is also $2,500. Connecticut's is $3,000.

The state rebates are in addition to the $7,500 buyers can get in federal tax credits.

The money for Rhode Island's program is distributed by the state attorney general's office. It stems from money awarded in a lawsuit brought by several states and the federal government against the American Electric Power Service Corporation.