U.S. President Joe Biden plans to announce Friday that the U.S. will contribute $2 billion to a U.N.-backed program seeking to distribute COVID-19 vaccine doses to the world's poorest nations, Axios reported, citing a seniorWhite House officials.

The U.S. will give an additional $2 billion over the next two years through the COVAX program, the officials announced ahead of Friday's virtual G7 summit. The move comes as the U.S. grapples with not yet getting enough doses to immunize its own population, though the situation in poorer countries is far worse.

"This pandemic is not going to end unless we end it globally," NPR quoted a senior administration official as saying to reporters, noting the risk of new COVID-19 variants developing and spreading.

Biden's action is a sharp departure from his predecessor Donald Trump's threat to back out of the World Health Organization, which he claimed was being too close to China, where the novel coronavirus was first detected in late 2019.

France will donate 5% of its secured supplies to the initiative while the UK also will announce the commitment during the G7 summit, a meeting of th world's top economies to start Friday via livestream, according to Bloomberq. Novavax separately announced it will supply more than 1 billion doses of the vaccine to COVAX.

To date, 10 nations have used 75% of all COVID-19 vaccines, while more than 130 countries have yet to get a single shot, the United Nations said Thursday.

The vaccine alliance GAVI, which helps lead COVAX, in November said that more than $2 billion had been allocated to acquire COVID-19 vaccines, but at least $5 billion more was needed.

COVAX targets to roll out at least 2 billion vaccine doses by the end of the year to cover almost a quarter of the most vulnerable people in poor and middle-income nations.

The U.S.' vaccine supply is expected to double in the next few weeks and months, based on an analysis by Bloomberg, although winter storms across the country continue to hinder the vaccination campaign.