By Ahmed Aboulenein and Chris Gallagher

WASHINGTON (Reuters) -A military cargo plane carrying the first shipment of infant formula from Europe to help address a critical shortage in the United States landed in Indianapolis on Sunday, and the White House said a second flight had been arranged.

A Feb. 17 recall by top baby formula maker Abbott Laboratories and the closing of its manufacturing plant in Sturgis, Michigan during an investigation by the U.S. Food and Drug Administration has created one of the biggest infant formula shortages in recent history for U.S. families.

“This is an important step, but it is by no means the only step that must take place. We will continue to work as the president has instructed us to look for every opportunity to increase supply,” said Agriculture Secretary Tom Vilsack, who greeted the plane on its arrival.

“This particular formula is for a very, very small percentage of children. Roughly 17,000 children in the country basically are the beneficiaries of this particular formula,” he said.

President Joe Biden’s administration is seeking to stock empty shelves with 1.5 million containers of Nestle specialty infant formulas. Biden last week invoked the Cold War-era Defense Production Act to help increase supplies.

The White House said on Sunday a second flight carrying formula would leave from Ramstein Air Base in Germany in coming days. The White House said that Abbott and a second baby formula maker, Reckitt, were the first companies given priority status for raw supplies under the Defense Production Act.

Nestle also said more shipments would arrive in the coming days.

Troops used forklifts to unload boxes of the cargo from the plane in Indianapolis and onto trucks heading to distribution centers. The White House said 78,000 pounds (35,000 kg) of specialty infant formula – enough for 500,000 bottles – had arrived on the flight.

Abbott, the biggest U.S. supplier of powder infant formula, closed its Michigan plant following reports of bacterial infections in four infants, worsening a shortage among multiple manufacturers that began with supply-chain issues tied to the coronavirus pandemic.

Abbott Chief Executive Robert Ford apologized for the shortage on Sunday and promised to fix it, adding the plant would reopen in the first week of June, and it would take six to eight weeks for products to reach store shelves.

“We’re sorry to every family we’ve let down since our voluntary recall exacerbated our nation’s baby formula shortage,” he wrote in a Washington Post column.

New York City Mayor Eric Adams on Sunday declared a state of emergency to prevent price gouging of baby formula.

“This emergency executive order will help us to crack down on any retailer looking to capitalize on this crisis by jacking up prices on this essential good,” Adams said in a statement.

(Reporting by Ahmed Aboulenein and Chris Gallagher, additional reporting by Jessica DiNapoli in Davos, Switzerland, Barbara Goldberg in New York and Dan Whitcomb in Los Angeles; Editing by Ross Colvin, Bill Berkrot, Chris Reese and Paul Simao)