(Reuters) - The White House said late Thursday that President Donald Trump intends to nominate a top auto-safety agency official to run the National Highway Traffic Safety Administration as regulators debate reducing planned fuel efficiency increases through 2025.

Heidi King, who was named deputy administrator in September, is slated to run the agency known as NHTSA that oversees auto safety and fuel efficiency rules.

King must be confirmed by the U.S. Senate before she can assume the position and will face questions on the agency’s approach to overseeing self-driving cars, the massive Takata recall and the agency’s lagging pace of completing some regulations required by Congress.

The biggest issue may be the agency’s plans to soften planned automaker fuel efficiency increases that have been met with furious resistance from environmentalists and many Democrats.

King told a Senate panel in March that the agency expected to propose fuel economy standards in April for a five-year period and is working “to make sure that the federal family is aligned in the path forward.”

NHTSA and the Environmental Protection Agency in 2011 in tandem set aggressive annual increases in fuel efficiency and emissions requirements, requiring a fleetwide estimated average of more than 50 miles per gallon by 2025.

The EPA agreed to conduct a “mid-term review” by April 2018 to determine if the 2022 through 2025 model year requirements are appropriate.

This week, EPA Administrator Scott Pruitt said those requirements are “not appropriate and should be revised.”

Car companies hope to avoid a potential legal battle among federal regulators, many state attorneys general and environmental groups. Automakers want rule changes to address lower gasoline prices and a shift in U.S. consumer preferences to larger, less fuel-efficient vehicles.

King, who joined the agency as deputy administrator last year, previously served in the White House’s Office of Management and Budget and also served two years as chief economist on the House Energy and Commerce Committee.

Asked for comment Thursday before the announcement after officials told Reuters Trump planned to make the nomination, a spokeswoman for King declined to comment.

NHTSA has a number of significant auto-safety investigations underway and is currently probing a fatal crash involving a self-driving Uber Technologies Inc [UBER.UL] vehicle in Arizona and a fatal crash involving a Tesla Inc vehicle in semi-autonomous “Autopilot mode.”

NHTSA also must decide whether to approve a petition filed by General Motors Co in January that seeks approval for a fully autonomous car - one without a steering wheel, brake pedal or accelerator pedal - for use in the automaker’s commercial ride-sharing fleet in 2019.

NHTSA previously came under fire for not doing more to uncover deadly defects involving GM ignition switches and Toyota Motor Corp unintended acceleration issues.

During the Obama administration, NHTSA boosted staffing levels and took a more aggressive stance than under previous administrations as automakers recalled a record number of vehicles.

The agency imposed record-setting fines on automakers who failed to quickly recall vehicles and often demanded companies agree to additional monitoring and oversight as the agency pushed for additional vehicle callbacks.

At a Senate hearing last month, King said more needs to be done to address the nearly 30 million U.S. vehicles that remain unrepaired in the Takata air bag inflator recall impacting 19 automakers.

At least 22 deaths and hundreds of injuries worldwide are linked to Takata inflators that can explode, unleashing metal shrapnel inside cars and trucks. The defect led Takata to file for bankruptcy protection in June.