The World Health Organization said it was monitoring a new variant of the coronavirus named mu, the 12th letter of the Greek alphabet.
Mu is scientifically known as B.1.621 and has been classified as a "variant of interest," the WHO said in its weekly pandemic bulletin on Tuesday.
The global health body said the variant has mutations that show a risk of resistance to COVID-19 vaccines, emphasizing that further studies were required to understand it better.
Since its detection, mu has been reported in South American countries and in Europe.