WASHINGTON (Reuters) - President Donald Trump's nominee to serve as deputy secretary of the U.S. Transportation Department said regulators need to take a more aggressive approach to overseeing planemaker Boeing ( BA ).

"We need to be tougher on Boeing ( BA ). We need to be tougher on the industry," said Steve Bradbury at a U.S. Senate Commerce Committee hearing Thursday.

Senators questioned Bradbury about whether during Trump's first term he intentionally withheld documents from a Senate probe into two fatal 737 MAX crashes that killed 346 people in 2018 and 2019. At the time he was the Transportation Department's general counsel and the Senate was seeking Federal Aviation Administration documents.

Bradbury told senators that at the time, his department was overwhelmed with requests for information and was attempting to provide documents, not impede or block the investigation.

Last month, Transportation Secretary Sean Duffy told Congress that Boeing ( BA ) needed "tough love" and he would keep in place a cap on production of Boeing 737 MAX planes put in place after a mid-air panel blowout last year until he is satisfied it can be safely raised.

In January 2024, former President Joe Biden's FAA chief Mike Whitaker imposed the 38 planes per month production cap after a door panel missing four key bolts flew off a new Alaska Airlines 737 MAX 9. President Donald Trump has yet to nominate a candidate for FAA administrator.

Duffy, who plans to travel to Seattle with acting FAA Administrator Chris Rocheleau to meet with Boeing ( BA ) in March, said last week he wants to "evaluate firsthand the measures being implemented to ensure its planes meet the highest safety standards."

In May 2022, the FAA approved a three-year renewal of a Boeing ( BA ) program that delegates some aircraft certification tasks to the planemaker rather than the five-year renewal Boeing ( BA ) had requested. The approval will expire in a few months.