(BBC) – US President Joe Biden’s administration will provide 500 million doses of the Pfizer Covid-19 vaccine to about 100 countries over the next two years, US media report.
About 200 million doses will be distributed this year, with the remainder delivered in 2022.
The US has been under pressure to raise vaccination rates in poor countries.
The move comes as Mr Biden landed in the UK at the start of his first foreign trip as US president.
The White House is yet to officially comment on the plan to roll out 500 million doses worldwide.
But when asked if the US government had a vaccination strategy for the world, Mr Biden said: “I have one, and I’ll be announcing it,” before boarding Air Force One.
An eager crowd awaited his arrival on Wednesday at the RAF Mildenhall airbase in Suffolk, keen to catch a glimpse of Air Force One when Mr Biden touched down on Wednesday evening.
Mr Biden addressed US troops stationed at the base, paying tribute to military families and remembering his late son, Beau, who served in the National Guard.
He praised US allies – “like-minded nations” – and added: “The United States is back!”
“Democracies of the world are standing together to tackle the toughest challenges and the issues that matter most to our future,” he said.
Mr Biden later travelled on to Cornwall. The US president and Prime Minister Boris Johnson will meet for the first time on Thursday, ahead of the G7 summit in the south-western corner of England.
Also in his eight-day trip Mr Biden will meet the Queen at Windsor Castle and join his first Nato summit as president. He has said the visit is about “America rallying the world’s democracies”.
What do we know about the 500 million jabs?
The US government will donate the vaccines to 92 lower-income countries and the African Union, Reuters news agency reports.
Distribution will go through the Covax scheme, which was set up last year to try to ensure fair access to vaccines among rich and poor nations.
The US had previously said it would donate 60m vaccine doses through Covax.
People familiar with the deal told the New York Times that the US would pay for the doses at a “not-for-profit” price.
Albert Bourla, chief executive of Pfizer, is expected to appear with Mr Biden when he officially announces the initiative on Thursday.
The UK and Canada have not yet said how many doses they will provide to the Covax scheme.
What can we expect from the G7 summit?
The G7 (Group of Seven) is made up of the world’s seven largest so-called advanced economies – Canada, France, Germany, Italy, Japan, the UK and the US – plus the EU.
Other G7 leaders will arrive in Cornwall on Friday, and meetings will get under way the following morning.
The main topic of conversation will be Covid recovery, including “a stronger global health system that can protect us all from future pandemics“.
The agenda also includes climate change and trade.
Mr Biden is expected to warn that the ongoing UK-EU trade row could imperil peace in Northern Ireland. He will call on fellow leaders to protect the gains of the Good Friday agreement.
At the end of the summit, the UK – as the host nation – will publish a document outlining what has been agreed by the leaders.