G7 leaders will agree to expand global Covid vaccine manufacturing to provide at least one billion doses to the world through sharing and financing schemes, Britain said Thursday.
The announcement came after the United States said it would donate 500 million jabs to 92 poor and lower-middle-income nations.
The UK, which is hosting the big powers' gathering in southwest England, added it would donate at least 100 million surplus doses within the next year, including five million beginning in the coming weeks.
The commitments follow growing calls for richer countries to step up their efforts to share Covid-19 shots with less developed nations, with charities warning the current situation is leading to "vaccine apartheid".
Britain, which has orders for more than 400 million doses, has faced criticism for failing to begin making donations to poorer countries.
But on the eve of welcoming world leaders from the group of seven wealthy nations to their first summit in almost two years, British Prime Minister Boris Johnson vowed that would soon change.
"As a result of the success of the UK's vaccine program we are now in a position to share some of our surplus doses with those who need them," he said.
"At the G7 Summit I hope my fellow leaders will make similar pledges".
A Downing Street statement said: "At the Summit world leaders are expected to announce they will provide at least one billion coronavirus vaccine doses to the world.. and set out a plan to expand vaccine manufacturing in order to achieve that goal."
Meanwhile EU members have agreed to donate at least 100 million doses by the end of 2021 -- with France and Germany each committing to providing 30 million.
French President Emmanuel Macron issued his own call for pharma groups producing vaccines to donate 10 percent of their production to poor nations.
US President Joe Biden on Thursday saluted a "historic" moment in the fight against the pandemic after Washington announced its donation.
"This is about our responsibility, our humanitarian obligation to save as many lives as we can," Biden told reporters at the start of his first overseas trip as president.
AFP quoted Biden as saying that the move was also in the US interest because of the risk of variants while the White House said the decision would "supercharge the global fight against the pandemic".