DAVID SHEPARDSON US President Joe Biden will impose a ban on most non-U.S. citizens entering the country who have recently been in South Africa starting this weekend in a bid to contain the spread of a new variant of COVID-19, U.S. public health officials told Reuters. Biden today is also reimposing an entry ban on nearly all non-U.S. travellers who have been in Brazil, the United Kingdom, Ireland and 26 countries in Europe that allow travel across open borders, said the sources, who requested anonymity because the plans have not yet been made public. Then-President Donald Trump directed on January…