The U.S. government will send 25 million COVID-19 vaccine doses to foreign countries across Asia, Africa and Latin America, the first time President Joe Biden’s administration has shared shots it could have used at home.

Through the UN-organized Covax program, the U.S. plans to distribute six million shots to Central and South America, seven million to Asia including hard-hit India and five million to Africa, the White House said in a statement.

The U.S. will directly send another six million shots to countries including Mexico, Canada, South Korea and the Palestinian territories, the White House said.

The move is a watershed moment for the U.S., which secured the first hundreds of millions of doses made on its soil for domestic use but intends to be an engine of vaccine production globally. As vaccine demand wanes at home, Biden is facing calls internationally to release the American stockpile of shots made by Pfizer Inc., Moderna Inc. and Johnson & Johnson in order to curb the rise of coronavirus variants against which existing vaccines might provide less protection.

Administration officials have consulted with vaccine manufacturers and international organizations on aspects of the operation, including transportation logistics and legal requirements, one person familiar with the plans said.

Thursday’s announcement will include a framework to distribute shots among countries based on need. Biden has said his administration will donate 80 million doses by the end of this month, including 60 million that aren’t yet available for use.

Nonetheless, the move is a sign of a cresting wave of American vaccine production poised to meet world demand. The gap between U.S. doses delivered and actually administered has risen to 70 million -- much of which are in various stages of distribution. But the figure is an indication of the U.S. glut Biden has to work with.

Another 60 million doses of AstraZeneca Plc’s vaccine remains on U.S. shelves, despite Biden’s repeated promises to export them. That shot has not been authorized for U.S. use and is still under review by the Food and Drug Administration.

In addition to the Biden administration’s plans to begin sharing doses it bought, Pfizer and Moderna have both begun filling international orders from U.S. plants that previously supplied only the U.S. government.

Harris is set to meet with the leaders of Mexico and Guatemala next week on a trip through the region. Mexico and other countries have publicly asked the U.S. to share its vaccines, and some European allies had criticized Biden for hoarding U.S. production.

Next week, the president will leave for his first international trip, a series of stops in Europe including meetings of the Group of 7 nations, NATO and the European Union. A summit in Geneva with Russian President Vladimir Putin is also planned.

In the U.S., 297 million doses of vaccines have been administered so far. In the past week, an average of 1.1 million doses per day were administered, down significantly from just several weeks ago.

Biden has said he will not use U.S. vaccines as a diplomatic tool, after accusing China and Russia of leveraging doses of their vaccines for foreign policy gains.