The World Health Organisation has urged countries around the world not to impose flight bans on southern African nations due to concerns over the new Omicron Covid-19 variant.

WHO's regional director for Africa, Matshidiso Moeti, called on countries to follow science and international health regulations in order to avoid using travel restrictions.

"Travel restrictions may play a role in slightly reducing the spread of Covid-19 but place a heavy burden on lives and livelihoods," Moeti said in a statement. "If restrictions are implemented, they should not be unnecessarily invasive or intrusive, and should be scientifically based, according to the International Health Regulations, which is a legally binding instrument of international law recognised by over 190 nations."