Top infant formula makers, including Reckitt Benckiser, Nestle and Danone SA, are also ramping up supplies to the country.
Here is a timeline on how the crisis unfolded and the measures being taken to resolve it:
Abbott recalls dozens of types of powdered baby formulas, including Similac, Alimentum and EleCare, made at its Sturgis, Michigan plant after four consumers complained about bacterial infections in infants who had consumed those products; Recalled products had an expiry date of April 1, 2022 or later.
China's custom officials warn consumers against buying and consuming certain of Abbott's infant and baby products.
Abbott expands recall to include some Similac PM 60/40 products based on a fifth complaint of a bacterial infection.
House Appropriations Committee Chairwoman Rosa DeLauro into the FDA's handling of the Abbott recall.
FDA probe of Abbott's Michigan facility finds a harmful bacteria called Cronobacter sakazakii on the surface of some areas near infant formula production, and reveals Abbott did not have a control system in place to prevent microbe contamination.
Abbott, calling the recall a "short-term hindrance", cuts its full-year sales growth forecast but maintains profit estimate.
House Appropriations Committee Chair Rosa DeLauro in a testimony submits a report acquired from a whistleblower, who had worked at the Abbott facility and had filed a complaint with the FDA in September 2021.
Abbott says it will release some nutrition products made at its Michigan plant on a case-by-case basis.
Major U.S. retailers including Target Corp, CVS Health Corp, Walgreens Boots Alliance and Kroger Co place purchase limits on infant formula products.
Abbott says it has been prioritizing production of formula at other plants, and shipping formula from its Ireland facility.
President Joe Biden meets with executives from baby formula manufacturers and retailers including Target, Walmart and Nestle's Gerber to address the shortage.
Store-brand baby formula maker Perrigo Co says shortages and heightened demand may last for the rest of the year.
The U.S. House Oversight Committee plans to investigate the shortage, saying it has sent letters seeking information to the four largest manufacturers of baby formula - Abbott Nutrition, Mead Johnson Nutrition, Nestle USA and Perrigo.
U.S. Centers for Disease Control and Prevention (CDC) closes its investigation on Abbott, while Abbott said it has air shipped millions of cans of baby formula powder into the United States from its facility in Ireland.
The FDA says the United States will allow imports of infant formula from foreign makers that do not usually sell their products in the country.
Abbott reaches agreement with the FDA on the steps needed to resume production at its Michigan plant.
U.S. House Democrats unveil a bill to provide $28 million in emergency funds to the FDA to help it respond to the shortage and bolster supervision of the industry.
Nestle SA told Reuters it was flying supplies to the country from the Netherlands and Switzerland. Reckitt Benckiser, the second largest U.S. milk formula supplier, is boosting baby formula production by about 30%.
U.S. President Biden invokes the Defense Production Act to help manufacturers obtain the ingredients needed to ramp up supply.
French baby formula maker Danone SA has ramped up shipments of infant formula from Europe to the United States, according to U.S. customs data and shipping consultancy Ocean Audit.
Abbott says it plans to restart production at the facility on June 4.
The U.S. Federal Trade Commission launches an inquiry into the ongoing shortage and to examine past M&A deals in the formula market to understand their impact.
Danone says it has been doubling shipments to the United States of Neocate formula, while Enfamil maker Reckitt is also working to boost supplies amid a nationwide shortage.
(Reporting by Deborah Sophia and Leroy Leo in Bengaluru; Editing by Anil D'Silva and Sriraj Kalluvila)