US President Joe Biden will reinstate a ban on most non-US citizens entering the country, including people from Brazil and the United Kingdom where new, more transmissible variants of the coronavirus have emerged in recent months, and add South Africa to the restricted list, according to public health officials.

“We are adding South Africa to the restricted list because of the concerning variant present that has already spread beyond South Africa,” Dr Anne Schuchat, the principal deputy director of the Centers for Disease Control and Prevention (CDC), said in an interview with the Reuters news agency.

Arrivals from Ireland and 26 countries in Europe that allow travel across open borders will also be banned.

She added that the CDC was “putting in place this suite of measures to protect Americans and also to reduce the risk of these variants spreading and worsening the current pandemic.”

The move overturns a last-gasp decision from former President Donald Trump that the restrictions on Brazil and Europe be lifted from January 26 when new testing requirements are also due to come into force.

Biden, who took office on Wednesday, is taking an aggressive approach to combating the spread of the virus after Trump rejected mandates sought by health agencies and downplayed the severity of the pandemic. More than 25-million people in the United States have now been confirmed with Covid-19, about a quarter of the world’s total infections.

The South African variant, also known as the 501Y V2 variant, is 50 percent more infectious and has been detected in at least 20 countries.

The South African variant has not yet been found in the US but at least 20 US states have detected a UK variant known as B117, which is also significantly more transmissible. While current vaccines appear effective against the UK mutations, there are concerns the South African variant might be more resistant.

Mask up

The Centers for Disease Control and Prevention director (CDC) head Rochelle Walensky will sign a separate order on Monday requiring masks on all forms of public transport including taxis and ride-share vehicles for all travellers aged two and above, officials said. The new requirements are set to take effect in the coming days, they said and masks can be removed for brief periods while eating or drinking.

New CDC rules are already due to take effect on Tuesday requiring all international air travellers above the age of two to present a negative coronavirus test taken within three calendar days of travel or proof of recovery from Covid-19 to enter the US.

The CDC will not, as it said on January 12, consider granting temporary waivers to airlines to exempt some travellers from countries with limited testing capacity, but humanitarian exemptions will be considered on a case-by-case basis.

CDC officials noted 120 countries currently have mandatory Covid-19 testing requirements for international travel.

Under the order, international arrivals will have to self-quarantine for seven days and consider taking a new Covid-19 test within three to five days of returning to the US.

“With the pandemic worsening and these more contagious variants emerging it’s not the time to lift restrictions on international travel,” Schuchat said.

CDC officials have for also been discussing the possibility of adding these testing requirements to domestic flights but have made no decisions.

The restrictions barring most visitors from Europe have been in place since mid-March, while the Brazilian entry ban was imposed in May. The restriction, along with the new South Africa ones, mean most people who are not US citizens and have been in one of those countries within the last 14 days will not be able to travel to the US.

Permanent residents and family members, and some other non-US citizens, are permitted to return home under the order.

Under Trump, the CDC push to mandate masks in transit was blocked and the agency instead only issued strong recommendations for mask use.