The Biden administration is placing travel restrictions on several African countries amid the rise of the Omicron, a new variant of COVID-19 discovered in South Africa, the New York Daily News reports. The countries that fall under the travel ban are Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, and Zimbabwe.

On Friday, the World Health Organization identified the new variant as Omicron—which is named after the 15th letter of the Greek alphabet—recognized it as the latest strain, CNBC reported.

White House chief medical advisor Dr. Anthony Fauci briefed Biden on Friday as several other countries instituted restrictive traveling measures. Canada, the European Union, and the U.K. all announced heightened restrictions on travelers from southern Africa on Friday.

Restrictions will not apply to returning U.S. citizens or permanent residents, who will continue to be required to test negative before traveling back to the U.S.

“The news about this new variant should make clearer than ever why this pandemic will not end until we have global vaccinations,” President Joe Biden said in a statement. “The United States has already donated more vaccines to other countries than every other country combined. It is time for other countries to match America’s speed and generosity.”

"I've decided we're going to be cautious," Biden said to reporters Friday following the announcement of the travel restrictions. "We don't know a lot about the variant except it is a great concern, seems to spread rapidly,"

The move comes as a result of Great Britain becoming the most recent to ban flights from South Africa over Omicron, which has already likely spread to border countries in the region. Britain's Health Security Agency has acknowledged that two confirmed cases of Omicron have been discovered in the U.K.

Just last month, the U.S. ended its COVID travel restrictions for certain countries and introduced a blanket requirement that all travelers must be fully vaccinated.

In comparison to other international destinations, flights between the U.S. and South Africa are very limited but the drastic sudden changes in travel rules could further delay the return of international business travel.