The Biden administration on Thursday announced it will donate 25 million coronavirus doses abroad, with about three quarters of them allocated to the World Health Organization's COVAX initiative, and the rest donated directly to handpicked countries.

"We are sharing these doses not to secure favors or extract concessions. We are sharing these vaccines to save lives and to lead the world in bringing an end to the pandemic, with the power of our example and with our values," President Biden said in a statement.

The White House said it will donate about 19 million doses to COVAX, which purchases and distributes vaccines to low-and middle-income countries. Administration officials said about 6 million doses will go to Latin America and the Caribbean, 7 million doses will go to Asia, and 5 million will go to Africa.

Additionally, about 6 million doses will go directly to countries in need, including Mexico, Canada and South Korea, and to United Nations front-line workers.  

Pressure has been growing on the White House to develop a plan to donate its excess vaccines to countries that have been hit hard by the virus without the same access to vaccines as wealthier nations. One concern is that without vaccinations, new variants of the virus may arise in those countries that could threaten the rest of the world.

Thursday's announcement, which comes ahead of the Group of Seven Summit next week, stops short of the 80 million total doses promised by the administration last month. Instead, it focuses only on the authorized vaccine doses from Pfizer-BioNTech, Moderna and Johnson & Johnson. 

Biden has said the U.S. will donate “at least” 20 million of those by the end of June.

He has also pledged to donate 60 million doses of AstraZeneca's vaccine, which is not authorized for use in the U.S., but that effort has been hamstrung by manufacturing safety concerns and a related Food and Drug Administration review. It's still not clear when, or even if, the FDA review will be complete and the doses will be cleared.

"We will continue to donate additional doses across the summer months as supply becomes available,” White House coronavirus coordinator Jeff Zients told reporters Thursday. 

To date, most of the U.S. international support has come in the form of money, with the administration committing $4 billion to COVAX.

The administration earlier agreed to give 4.2 million doses of vaccines to Mexico and Canada — the only U.S.-owned doses that have been sent abroad.

The Biden administration has been facing growing calls to help bolster the global vaccination effort as demand and enthusiasm for vaccines wane in the U.S. while other countries face a crisis. 

According to the World Health Organization, the U.S. and other high-income countries have secured almost 90 percent of the available coronavirus vaccine supply.

The administration had initially been reluctant to send any doses overseas, saying the extra doses could be a backstop for possible manufacturing issues in the U.S., used to vaccinate children or serve as booster doses if necessary to fight against variants of the virus.

Now, administration officials are confident in the supply.

"Importantly, we have secured enough vaccine supply for all Americans," Zients said. More than half of all Americans have received at least one dose of a coronavirus vaccine so far, according to the Centers for Disease Control and Prevention.

As a result, Zients said the U.S. will remove the Defense Production Act priority ratings on the not-yet authorized vaccines from AstraZeneca, Novavax and Sanofi. That will free the companies from obligations to supply the U.S. ahead of other countries.

"While the manufacturers will continue to make these three vaccines, this action will allow U.S. based companies that supply these vaccine manufacturers to make their own decisions on which orders to fulfill first," Zients said.

Updated at 12:40 p.m.