"The President feels good, is not seriously ill and is under constant medical supervision," top aide Pawel Szrot said in a tweet. He said the president was in isolation, Reuters reported.

Duda also caught coronavirus in October 2020.

Poland has reported a lower number of new COVID-19 infections in recent days, but reporting is likely to have been influenced by a reduction in testing over the holidays.

The Omicron variant has yet to gain a foothold in Poland - the ministry of health said on Tuesday it was responsible for around 2.5% of infections, but it was expected to become dominant by the end of the month.