WASHINGTON — President Donald Trump’s nominee to head the powerful Food and Drug Administration told senators Wednesday that tackling the opioid crisis would be a top priority and pledged that science will prevail despite his extensive financial ties to medical companies the agency regulates.

Dr. Scott Gottlieb is a physician-turned-health consultant who has criticized what he calls unnecessary FDA regulations and has what critics call his unprecedented financial entanglements. But Gottlieb told a Senate health committee that impartial science does and must continue to guide FDA’s decisions.

Gottlieb said that as a cancer survivor, he knows firsthand the importance of “what the FDA does for every one of us” and stressed the balance between speeding drugs to the market and making sure enough is known about their safety.

“We save lives by allowing good things to happen, but we also save lives when we prevent bad things from happening,” Gottlieb said, calling FDA’s enforcement rules “the bedrock of its mission.”

Among his top priorities, Gottlieb said, would be tackling opioid addiction, what he called “the biggest crisis facing the agency,” through development of non-addictive alternatives as well as addiction treatments.

Gottlieb is no stranger to the FDA, which regulates products that affect about a quarter of all consumer spending — everything from new drugs and medical devices to food safety, nutrition labeling, tobacco and e-cigarettes and cosmetics. He was a deputy commissioner under President George W. Bush.

“My hope is that you will help move the agency forward so that America’s patients benefit from the remarkable discoveries our nation’s researchers are working on,” said Sen. Lamar Alexander, R-Tenn., who chairs the health committee.

But critics have focused on Gottlieb’s finances, citing government data showing he received hundreds of thousands of dollars in consulting or other fees from several FDA-regulated companies in recent years, including giant GlaxoSmithKline and Vertex Pharmaceuticals.

In ethics documents filed last week, Gottlieb said that if confirmed he would recuse himself for a year from decisions involving about 20 companies. He also said he would resign from positions in a venture capital firm and investment bank that fund health companies, and as a board member or consultant to nine other health-related companies. Gottlieb’s day job is as a resident fellow at the conservative American Enterprise Institute, from which he said he also would resign.

But Sen. Patty Murray of Washington, the committee’s senior Democrat, questioned whether recusals are enough to erase the bias of being a pharmaceutical industry insider when dozens of drugs being developed by those companies could come before the FDA.

“What I’m concerned about is how your involvement with so many companies shapes your priorities,” she said.

Gottlieb responded, “I get it. I understand how important the impartiality of this agency is so people continue to have trust in the decisions FDA makes.”

“I want to earn and keep the public’s trust,” he said.