The White House on Thursday vowed to take action to boost supplies of baby formula as US President Joe Biden was slammed by Republicans for nationwide shortages.
Last week, the average out-of-stock rate for baby formula was 43 per cent, according to Datasembly, which collected information from more than 11,000 retailers.
The administration, already under fire over the highest inflation rate in decades, did not specify what action it might take but said Mr Biden would speak to manufacturers and retailers later on Thursday.
The shortages have been worsening since February 17 when, after the death of two infants, manufacturer Abbott announced a “voluntary recall” for formula made at its factory in Michigan — including Similac, a brand used by millions of American families.
A subsequent investigation cleared the formula, but production has yet to resume, exacerbating already ongoing scarcity caused by supply chain problems and labour shortages.
Republicans, who have set their sights on wresting back control of Congress in November's midterm elections, have seized on the issue to berate Mr Biden and the Democrats.
Elise Stefanik, part of the House Republican leadership and a new mother herself, told a news conference she had contacted the US Food and Drug Administration in February but received “no substantive response”.
“Joe Biden simply has no plan. In fact, when Joe Biden's White House was asked about the shortage, they laughed. Shameful,” she told reporters.
Her Republican House of Representatives colleague Anne Wagner of Missouri said her state was one of six in which more than half of the normal supply of baby milk was out of stock.
“I've heard stories of mums first-hand — my own daughter-in-law — bartering for baby formula on Facebook,” she said.
“Pregnant women are asking if they should start stockpiling. They're anxious during a time of high stress and anxiety.”
Randy Feenstra, a US representative from Iowa, said families in his state were travelling up to 160 kilometres to source formula.
-AFP contributed to this report