President Joe Biden announced the US will impose travel restrictions on eight southern African countries due to the new Covid-19 variant Omicron, joining efforts with other countries to mitigate its spread.
The nations include South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi.
The variant was first detected in South Africa. Cases have also been detected in Belgium and Botswana.
In a statement announcing the travel restrictions, Mr Biden called for a greater amount of shots in American arms and across the world.
“The news about this new variant should make clearer than ever why this pandemic will not end until we have global vaccinations,” Mr Biden said in a statement.
Mr Biden also called for a greater global effort in vaccine distribution to poorer countries and to waive intellectual property protections on vaccines so they can be manufactured globally.
The US is planning to invest billions of dollars in manufacturing a Covid-19 vaccine with the aim of administering those doses early next year.
The new travel limit “was implemented out of an abundance of caution”, NBC reported on Friday, citing senior administration officials.
The ban does not apply to American citizens and lawful permanent residents, though they must still test negative before travelling to the US, Bloomberg reported.
On Friday, the World Health Organisation designated the B. 1.1.529 Omicron strain as a “variant of concern” following an emergency meeting prompted by a rapid spike of cases in South Africa, where at least 77 cases have been detected.
“This variant has a large number of mutations, some of which are concerning. Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other [variants of concern]," the WHO said in a statement.
“This variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage.”
Countries across Europe halted air travel from the region earlier in the day, as did Canada.
Top US infectious disease specialist Dr Anthony Fauci said earlier on Friday that US scientists would meet South African researchers to “really get the facts” about the situation.
It is still too early to determine how transmissible the new variant is or how effective vaccines are against it.
The move by the US is an abrupt change for the US, which this month lifted international travel restrictions for fully vaccinated travellers.
The US Transportation Security Administration is expected to screen about 20 million air travellers during Thanksgiving week.
Agencies contributed to this report
