A top EPA official said Thursday that the agency aims to maintain “one national program” for vehicle-emissions rules and wants to avoid a legal battle with California over environmental regulations on cars and trucks.

“This obviously is a very important issue and I have no interest whatsoever in withdrawing California’s ability to regulate,” said EPA Assistant Administrator Bill Wehrum, who leads the agency’s Office of Air and Radiation, during a briefing at the Washington Auto Show. “From a good solid public policy standpoint, the very best outcome for all of us to achieve is one national program.”

Last year, President Trump charged the EPA with reviewing rules set by the Obama administration that would require automakers to nearly double the average fuel economy of new cars and trucks to 54.5 miles per gallon by 2025.

Automakers have pressed for relief from the rules, arguing low gasoline prices have weakened consumer demand for hybrid-electric cars and smaller, fuel-efficient models.

The EPA has an April 1 deadline to decide whether the regulations covering the 2022-2025 model years should be revised.

California has fought the Trump administration over the proposed weakening of the rules.

Annette Hebert, an official with the California Air Resources Board, has warned the state could withdraw from the nationwide vehicle emissions program if the EPA limits the regulations.

California has an EPA waiver allowing it to set its own regulations that are tougher than the national standards, and other states can follow those instead.

In June, New York's Democratic attorney general, Eric Schneiderman, and 12 other state law enforcement officials that follow California’s standards said they would sue the Trump administration if it rolled back the rules.

Wehrum said Thursday the EPA has had “productive conversations” with the California Air Resources Board.

“We've heard loud and clear that having one national program is very, very important,” Wehrum said.

He said the EPA intends to meet the April 1 deadline for setting vehicle emissions standards, but he would provide little detail on how the administration is leaning.

“We are in the middle of the process, not at the end of the process, so I can't tell you where we are going,” Wehrum said. “Whatever we decide, it’s very important it is based on technical merits. It all begins with good analysis. It’s a very, very high priority of mine to ground what we are doing on good engineering and good science.”