President Biden pledged that the U.S. will donate 500 million additional doses of the Pfizer coronavirus vaccine to COVAX, a global initiative aiming to provide vaccines to developing countries.

“America will be the arsenal of vaccines in our fight against COVID-19, just as America was the arsenal of democracy in World War II,” Biden said. “The United States is providing these half-billion doses with no strings attached.”

According to a White House fact sheet, the U.S. will deliver 200 million doses in 2021 beginning in August, with the remainder to be donated in 2022. COVAX will be charged with the distribution of the vaccines, the fact sheet detailed, and they will go to 92 lower-income countries and the African Union.

Poor and developing nations continue to face mass vaccine shortages as inbound shipments stall. India, which is suffering a particularly severe outbreak, just recorded a devastating 6,000 deaths in a single day.

“As long as the virus rages elsewhere, there is a risk of new mutations that can threaten our people,” Biden said Thursday.

“This is a monumental commitment by the American people. … We’re going to help lead the world out of this pandemic working alongside our global partners.”

Earlier in the day, Biden had his first overseas bilateral summit, meeting with British Prime Minister Boris Johnson. Many parts of the United Kingdom have been ravaged by the virus, particularly by a unique strain known as the alpha variant. Now the delta, or “India,” variant has taken hold in the country. According to data from the New York Times, coronavirus cases in Britain have spiked by 131 percent and deaths by 22 percent from the average two weeks ago.

Like many other leaders, Johnson faces dueling economic and public health pressures on how rapidly and widely to reopen many parts of his country. Both Biden and Johnson have committed to resume travel between the U.S. and the U.K. soon, though the timeline is unclear.

The White House faced heavy scrutiny over its lack of vaccine sharing in the spring, when it allowed tens of millions of doses of the AstraZeneca vaccine to sit idly in warehouses while awaiting federal approval, despite having enough supply of the Pfizer, Moderna and Johnson & Johnson vaccines to adequately vaccinate all Americans. In March, 4 million of those idle doses were released to neighboring Canada and Mexico. In April, the White House announced it would send up to 60 million doses of the AstraZeneca vaccine out of the country as the pandemic was causing record-breaking death and infection in India.

Biden’s most recent pledge comes after other global vaccination commitments from the White House. In February, he pledged $4 billion to the COVAX alliance during his first virtual meeting with the G-7.

National security adviser Jake Sullivan told reporters aboard Air Force One that the White House is committed to multiple tactics to boost both vaccine supply and manufacturing overseas.

“We’re all converging around the idea that we need to boost vaccine supply in a number of ways, sharing more of our own doses,” Sullivan said. “We’ll have more to say on that, helping get more manufacturing capacity around the world.”