The US is flying in millions of cans of baby formula made from Australian goat and grass-fed cow milk as the battle to combat shortages continues.

The Food and Drug Administration said that at least 1.25 million cans of several varieties of infant formula will be provided by Bubs Australia.

The imports will be enough to make more than 27 million bottles. The FDA said more cans will be produced and sent in the coming weeks.

Increased flexibility outlined by the FDA allows more imports of baby formula from other countries. 98% of the baby formula consumed in America is produced by the US.

FDA Commissioner Robert Califf said that they continue to work around the clock to ensure there is adequate infant formula available.

More infant formula will be available to parents and caregivers in the weeks and months ahead, thanks to the steps the agency is taking today. We will not rest until we have safe and healthy infant formula on our shelves.

The move for increased flexibility follows historic shortages, with 40% of leading products out of stock and some paying $33 for a can, as wider supply chain shortages limit ingredient availability, exacerbated by a recall by maker Abbott over fears of babies becoming severely ill.

The makers of the baby formula used by the Royal Family said last week that they would send 100 truckloads of formula to the US.

In recent weeks, parents have been resorting to more desperate measures, with harmful formula recipes going viral on social media.