WASHINGTON — The head of the Food and Drug Administration told lawmakers Thursday that a shuttered baby formula factory could be up and running as soon as next week, though he sidestepped questions about whether his agency should have intervened earlier to address problems at the plant that triggered the national shortage.

Infant formula is stacked on a table during a baby formula drive to help with the shortage last week in Houston. David J. Phillip/Associated Press

FDA Commissioner Dr. Robert Califf faced a bipartisan grilling from House lawmakers over the baby formula issue that has angered American parents and become a political liability for President Biden.

The problems are largely tied to Abbott Nutrition’s Michigan formula plant, the largest in the U.S., which has been closed since February due to contamination problems. The FDA announced a preliminary agreement with Abbott earlier this week to restart production, pending safety upgrades and certifications.

“We had to wrestle this to ground with Abbott,” Califf told members of a House subcommittee “I think we are on track to get it open within the next week to two weeks.”

After production resumes, Abbott has said, it could take about two months before new formula begins arriving in stores. Califf said it will be “a few weeks” before supplies returns to normal levels, especially in rural areas.

When lawmakers asked why it took the FDA months to investigate a whistleblower complaint about safety violations at Abbott’s plant, Califf said he couldn’t share details due to the agency’s ongoing investigation. Several lawmakers rejected that response.

“It’s not acceptable to say you just can’t comment on it,” said Rep. Mark Pocan, D-Wisconsin. “This is a problem I’ve seen over and over with the FDA: You guys aren’t good at communicating.”

Califf is the first administration official to testify before Congress on the shortage, which has left some parents hunting for formula and become a political talking point for Republicans. On Wednesday evening Biden announced sweeping new steps to improve U.S. supplies, including invoking the Defense Production Act and flying in imported formula from overseas.

Rep. Rosa DeLauro, D-Conn., repeatedly asked Califf to explain what the FDA did after receiving a whistleblower complaint in October alleging numerous safety violations at Abbott’s plant, including employees falsifying records and failing to properly test formula before releasing it. The former Abbott employee wasn’t interviewed by the FDA until late December, and the plant wasn’t closed until mid-February, she noted.

“It all begs the question, why did the FDA not spring into action?” DeLauro asked. “Who in the leadership had access to that report – who didn’t have access to the report – and why was there no reaction?”

Califf said he had reviewed the complaint but didn’t specify when or what immediate steps were taken.

“I am committed to getting back to you on specifics of what happened, I’m just not prepared to today,” Califf said.

One point on which lawmakers and Califf agreed is that concentrated nature of the U.S. formula market makes it highly vulnerable to disruption. Just four companies produce an estimated 90 percent of U.S. formula, including Abbott, Gerber, Perrigo and Reckitt. Those companies also dominate federal contracts that provide about half of all U.S. formula through a program called WIC, for low-income mothers, children and babies.

Abbott shut its Michigan plant in February after FDA inspectors began investigating four bacterial infections in infants who had consumed formula from the plant. The first of those cases was reported to the FDA in September, but agency staff didn’t begin inspecting the facility until late January.

Califf said earlier this week the agency’s investigation is ongoing and it hasn’t yet reached a conclusion on whether bacteria from the plant caused the infant infections. Abbott has said there is no direct evidence linking its products to the illnesses.

The baby formula shortage is the first major crisis for Califf since returning to the FDA in February. He briefly led the agency under President Obama and was tapped for the job again based on his past experience leading the sprawling agency, which regulates food, drugs, medical technology and tobacco.

Thursday’s hearing was scheduled to review the FDA’s budget request for next year, and Califf asked lawmakers for $76 million in new funding for food safety and nutrition.

“I was very well aware coming in that we need to do major improvements on the food side of the FDA – not because the people are bad – but there is a need for consistent leadership and the right resources,” Califf told lawmakers.

The funding request comes amid longstanding concerns that the FDA’s food program – which oversees most U.S. foods except meat, poultry and eggs – has been underfunded and undermanaged compared to its medical divisions.

On Wednesday evening, House Democrats passed a $28 million spending bill that would boost FDA funding to inspect domestic and international formula producers. Its fate in the Senate is uncertain.

The subcommittee’s top Republican, Rep. Andy Harris of Maryland, said many of the problems facing the FDA could be “solved by strong leadership, rather than money.”

While supporting increased funding, DeLauro also said the problems in the agency’s food center run deeper.

“You have serious structural, leadership issues,” she told Califf. “Someone at this agency needs to have serious, relevant food credentials. Otherwise, food will be a second class citizen at the FDA.”

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.