WASHINGTON — The U.S. will begin sharing its entire pipeline of vaccines from AstraZeneca once the vaccine clear federal safety reviews, the White House said, with as many as 60 million doses expected to be available for export in the coming months.

The move greatly expands on the Biden administration's action last month to share about 4 million doses of the vaccine with Mexico and Canada. The AstraZeneca vaccine is widely in use around the world but not yet authorized by the U.S. Food and Drug Administration.

The move comes as the White House is increasingly assured about the supply of the three vaccines being administered in the U.S., particularly following the restart of the single-dose Johnson & Johnson shot over the weekend.

"Given the strong portfolio of vaccines that the U.S. already has and that have been authorized by the FDA, and given that the AstraZeneca vaccine is not authorized for use in the U.S., we do not need to use the AstraZeneca vaccine here during the next several months," said White House COVID-19 coordinator Jeff Zients. "Therefore the U.S. is looking at options to share the AstraZeneca doses with other countries as they become available."