(NewsNation) — A second emergency shipment of 100,000 pounds — equal to 1 million 8-ounce bottles — of baby formula arrived in Washington, D.C., from Germany Wednesday afternoon.

First lady Jill Biden and U.S. Surgeon General Vivek Murthy greeted the plane, making clear in a visit to the airport that fixing the baby formula shortage is a top priority for the administration.

In a speech, the first lady empathized with families.

“I’ve been heartbroken to hear the stories of parents searching for formula,” she said. “As a mom and a nana, it’s impossible to hear the stories of children suffering and not imagine your own children in the same position. Food is the first and most important way we nurture our children.”

The second shipment comes after 78,000 pounds of formula was flown in from Europe on Sunday as part of what the White House is calling Operation Fly Formula.

Operation Fly Formula is an effort to fly formula into the country amid a nationwide baby formula shortage leaving parents scrambling to find food for their infants.

Altogether, the two shipments had enough formula to fill 1.5 million baby bottles. The plane landed in Washington, after which the formula was to be taken up to a Nestle Distribution Center in Allentown, Pennsylvania, where employees are going to be working around the clock to unpack and distribute it.

The baby formula is hypoallergenic, which will help kids with cow milk allergies.

Also on Wednesday, Food and Drug Administration Commissioner Robert Califf testified about what led to the formula shortage, and why it took so long for the FDA to respond to the national crisis.

Califf faced bipartisan fury from House lawmakers over months of delays investigating problems at the nation’s largest baby formula plant that prompted an ongoing shortage.

Califf laid out in congressional testimony a series of setbacks that slowed his agency’s response, including a COVID-19 outbreak at the plant and a whistleblower complaint that didn’t reach FDA leadership because it was apparently lost in the mail.

Now, the Federal Trade Commission is investigating infant formula manufacturers to find out whether formula makers and distributors engaged in illegal economic discrimination that limited availability at some retailers.

Four manufacturers control 90% of the US market. It’s an issue made clear when the supply chain was disrupted after Abbott Industries took one of its plants offline in February because of contamination fears.

Several babies who ate formula produced at Abbott’s largest plant in Sturgis, Michigan, became ill, and two died.

The Abbott formula plant that shut down is expected to restart production on June 4, with the infant food becoming available to consumers beginning June 20.

Abbott officials told NewsNation that they are going to be giving out 300,000 cans of specialty formulas to families in need whenever that becomes available.

The Associated Press contributed to this report.