WASHINGTON (AP) -- President Joe Biden will announce Monday that the U.S. will share an additional 20 million doses of COVID-19 vaccines with the world in the coming six weeks, the White House said.

The doses would come from existing U.S. production of Pfizer, Moderna or Johnson & Johnson vaccine stocks, according White House press secretary Jen Psaki, who said more details would be released in the coming days. It would mark the first time that U.S.-controlled doses of vaccines authorized for use in the country will be shared overseas, as domestic demand for the shots has dropped significantly in recent weeks.

The announcement comes on top of the Biden's administration's prior commitment to share about 60 million doses of the AstraZeneca vaccine, which is not yet authorized for use in the U.S., by the end of June. The AstraZeneca doses will be available to ship once they clear a safety review by the Food and Drug Administration.

Biden is also tapping COVID-19 coordinator Jeff Zients to lead the administration's efforts to share doses with the world. The Biden administration has yet to announce how they will be shared or which countries will receive them.

To date, the U.S. has shared about 4.5 million doses of AstraZeneca vaccine with Canada and Mexico. Additional doses of the Pfizer vaccine manufactured in the U.S. have begun to be exported as the company has met its initial contract commitments to the federal government.

The U.S. has faced growing pressure to share more of its vaccine stockpile with the world as interest in vaccines has waned domestically.

More than 157 million Americans have received at least one dose of a COVID-19 vaccine, and 123 million are full vaccinated against the virus. Biden hopes the U.S. will have 160 million people fully vaccinated by July Fourth.

Globally, more than 3.3 million people are confirmed to have died from the coronavirus. The U.S. has seen the largest confirmed loss of life from COVID-19, at more than 586,000 people.