President Joe Biden said Monday that the U.S. will share an additional 20 million doses of COVID-19 vaccines with the world in the coming six weeks as domestic demand for shots drops and global disparities in distribution have grown more evident.

The doses will come from existing production of Pfizer, Moderna or Johnson & Johnson vaccine stocks, marking the first time that U.S.-controlled doses of vaccines authorized for use in the country will be shared overseas. It will boost the global vaccine sharing commitment from the U.S. to 80 million.

“We know America will never be fully safe until the pandemic that’s raging globally is under control,” Biden said at the White House.

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 also tapped COVID-19 coordinator Jeff Zients to lead the administration’s efforts to share doses with the world.

Also read: Bangladesh’s request for vaccine doses under active consideration: Miller

“Our nation’s going to be the arsenal of vaccines for the rest of the world,” Biden said. He added that, compared to other countries like Russia and China that have sought to leverage their domestically produced doses, “we will not use our vaccines to secure favors from other countries.”

The Biden administration hasn’t yet said how the new commitment of vaccines 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.

Also read: Will do our best to support vaccine rollout in neighbouring countries: India

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

“While wealthy countries continue ramping up vaccinations, less than 1 percent of COVID-19 vaccine doses globally have been administered to people in low-income countries,” said Tom Hart the acting CEO of the ONE Campaign. “The sooner the US and other wealthy countries develop a coordinated strategy for sharing vaccine doses with the world’s most vulnerable, the faster we will end the global pandemic for all.”

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.