He argued it was in both America’s interests and the world’s to make vaccination widely and speedily available everywhere.
“We’re going to help lead the world out of this pandemic working alongside our global partners,” Mr Biden said.
He added that tomorrow the G-7 nations would join the US in outlining their vaccine donation commitments.
His country has yet to send any doses abroad or announce a solid plan to share vaccines. Mr Johnson indicated Britain had millions of doses in surplus stocks.
“I think the European Union needs to have at least the same level of ambition as the United States” and be able to make a similar announcement, he said at a news conference.
Mr Biden said the US was sharing its doses “with no strings attached” or “pressure for favours”.
“We’re doing this to save lives, to end this pandemic, and that’s it,” he said.
Mr Biden had faced mounting pressure to outline his global vaccine sharing plan, especially as inequities in supply around the world have become more pronounced and the demand for shots in the US has dropped precipitously in recent weeks.
“In times of trouble, Americans reach out to offer help,” Mr Biden said, adding that the US doses would “supercharge” the global vaccination campaign.
“Our values call on us to do everything that we can to vaccinate the world against COVID-19.″
A price tag for the 500 million doses was not released, but the US is now set to be COVAX’s largest vaccine donor in addition to its single largest funder with a $US4 billion ($5.1 billion) commitment.
White House officials hope the ramped-up distribution program can be the latest example of a theme Mr Biden plans to hit frequently during his week in Europe: that Western democracies, and not rising authoritarian states, can deliver the most good for the world.
White House officials said the 500 million vaccines will be shipped starting in August, with the goal of distributing 200 million by the end of the year.
The remaining 300 million doses would be shipped in the first half of 2022.
After leading the world in new cases and deaths over much of the last year, the rapid vaccination program in the US now positions it among the leaders of the global recovery.
Nearly 64 per cent of adults in the US have received at least one vaccine dose and the average numbers of new positive cases and deaths in the US are lower now than at any point since the earliest days of the pandemic.
The Organisation for Economic Cooperation and Development last week projected that the US economy would grow at a rate of 6.9 per cent this year, making it one of the few nations for which forecasts are rosier now than before the pandemic.
US officials hope the summit will conclude with a communique showing a commitment from the G-7 countries and nations invited to participate to do more to help vaccinate the world and support public health globally.
Global public health groups have been aiming to use the G-7 meetings to press wealthier democracies to do more to share vaccines with the world.
Mr Biden’s plans drew immediate praise.
Tom Hart, acting CEO at The ONE Campaign, a non-profit that seeks to end poverty, said Biden’s announcement was “the kind of bold leadership that is needed to end this global pandemic.”
“We urge other G-7 countries to follow the US’ example and donate more doses to COVAX,” he added.
“If there was ever a time for global ambition and action to end the pandemic, it’s now.”
Others have called on the US to do even more.
“Charity is not going to win the war against the coronavirus,” said Niko Lusiani, Oxfam America’s vaccine lead.
“At the current rate of vaccinations, it would take low-income countries 57 years to reach the same level of protection as those in G-7 countries. That’s not only morally wrong, it’s self-defeating given the risk posed by coronavirus mutations.”