WASHINGTON — The Obama administration is close to saying what sort of gas mileage it envisions for cars of the future.

Environmentalists are pushing for an average of at least 60 miles per gallon for new vehicles by 2025, exceeding the mileage of the most fuel-efficient hybrids on the road today. But automakers argue that pushing gas mileage standards up that quickly could force them to raise prices higher than drivers can afford.

The administration is expected to give its view today in the form of early planning for mileage standards for model years 2017-2025. President Barack Obama has sought tougher fuel efficiency standards from the auto industry to reduce the nation's dependence on oil, and as part of his efforts to grow the economy through clean energy jobs.

Rules already in place will boost the fleet average to 35.5 mpg by 2016, an increase of more than 40 percent. Environmental groups say a mix of gas-electric hybrids, electric vehicles and improvements to conventional vehicles could create a vastly more efficient fleet. A target of 60 mpg by 2025 would translate to about a 6 percent improvement each year.

The government is also expected to soon release a proposal for first-ever fuel efficiency and emissions standards for medium-duty and heavy-duty trucks beginning with the 2014 model year.