US President Joe Biden has announced that the United States is surging exports of Covid vaccines to other countries to reclaim “American leadership” in the global fight against the pandemic, dismissing rival efforts by China and Russia.

Biden confirmed that 20 million more doses are being released over the next six weeks, bringing the total earmarked for shipping out by the end of June to 80 million, AFP reports.

The boost follows pressure on the Biden administration from other governments to use its large vaccine surplus to help struggling countries, now that significant progress has been made in rolling out vaccinations at home.

The initiative also addresses concerns that Moscow and Beijing have been taking advantage of the worldwide crisis to spread influence through distribution of their own national vaccines in a so-called “vaccine diplomacy” contest.