The United States is not assured of being fully safe from the coronavirus even with its high rate of vaccination unless it extends the global fight to defeat the variants from the scourge, US Agency for International Development (USAID) Covid-19 Task Force member, Jeremy Konyndyk said on Monday.

"We recognize that no matter how many people we vaccinated at home, the United States will not be fully safe as long as the virus rages on around the rest of the world and continues to replicate and generate new and potentially more dangerous," Konyndyk, who is assisting the Biden administration's global response to the coronavirus pandemic, said.

Konyndyk cited India as an example of the work that needed to be done in subduing mutations of the virus, with President Joe Biden pledging to Indian Prime Minister Narendra Modi last week a range of emergency assistance, including oxygen-related supplies, vaccine materials and therapeutics.

"[The] variants (and) current surge in South Asia really underscore the devastating consequences and risks of continued global transmission and the urgency of accelerating efforts to end the pandemic," Konyndyk said.

In a speech to Congress last month, Biden said the United States would become "an arsenal of vaccines" for other countries once vaccination targets for Americans were met. Biden said the United States would make 20 million additional vaccines available for other countries by the end of June from its reserves of Pfizer, Moderna and Johnson & Johnson shots.