The doses will be able to be exported in the coming months after a federal safety review.
The US has a stockpile of the vaccine even though its regulators have not yet authorised it for public use.
Critics have accused the government of hoarding the vaccine, while other countries are in desperate need.
Last month President Joe Biden pledged to share about four million doses of the AstraZeneca vaccine with Mexico and Canada - both of which have approved the jab.
The crisis in India has also piled pressure on the Biden administration to share US health resources.