The Environmental Protection Agency on Thursday rejected an auto industry request to extend the review period for strict new vehicle regulations, allowing them to go into effect before President Obama leaves office.

"The EPA continues to believe that the [decision] and the associated 30-day comment period remain appropriate and, therefore, the EPA is denying both the request for withdrawal and the request for an extension of the comment period," Janet McCabe, the EPA's air pollution chief, wrote in a letter to the top trade group for the automakers,the Alliance of Automobile Manufacturers.

The auto industry requested last month that the EPA extend the review period for an agency study that determined the new rules for improving fuel efficiency and lowering carbon emissions be extended into the next year.

The agency had surprised the industry last month by saying it was planning on finalizing its determination this year, instead of doing so next year as the law requires.

The EPA decision keeps the 54.5 mile-per-gallon fuel economy target for 2025 in place for light-duty cars and trucks.

The industry opposes the standard, saying it is too high and unachievable. It is already asking the incoming Trump administration to reverse the EPA's decision.

The alliance has said that low gasoline prices are driving up sales of sport utility vehicles and light trucks, which undercuts the target that is supposed to be reached by selling more electric cars.