Following a British ban on flights from southern African countries, South Africa said on Friday that placing restrictions on visitors from the country due to a newly found COVID-19 variant was unnecessary.

Health Minister Joe Phaahla told a media conference that South Africa was operating transparently and that travel prohibition violated World Health Organization (WHO) regulations and guidelines, which conducted an emergency meeting over the variant known as omicron.

So far, scientists have discovered the variant in relatively tiny numbers, primarily in South Africa, but also in Botswana, Hong Kong, and Israel. However, they are concerned about its large number of mutations, which raises the possibility that it may be more vaccine-resistant and transmissible.

The WHO designated omicron as "of concern," its most serious level, following a meeting of its technical advisory group.

According to a Downing Street official, British Prime Minister Boris Johnson and South African President Cyril Ramaphosa talked on Friday afternoon and discussed options to restore international transit.

"Our immediate concern is the damage that this decision will cause to both the tourism industries and businesses of both countries," South African Foreign Minister Naledi Pandor said in a statement.

On Sunday, Ramaphosa will meet an advisory group to review evidence on the variant.

The rand fell by up to 2% versus the dollar, and South African hospitality stocks dropped as investors became concerned.

Britain declared the variant to be the most significant discovered to date and prohibited flights from South Africa, Botswana, Lesotho, Eswatini, Zimbabwe, and Namibia. The European Union has also agreed to prohibit travel to southern Africa, according to the EU president.

Salim Abdool Karim, one of South Africa's best epidemiologists, said a worldwide reaction was critical, adding that the delta variant spread to 53 nations in three weeks after it was discovered.