Tennis star Novak Djokovic appears likely to miss two of the season's most prestigious tournaments in the spring after American border control bosses extended the rule forbidding unvaccinated foreigners from entering the country.
The Department for Homeland Security said proof of anti-coronavirus jabs will be needed to get into the United States until at least 10 April.
That will exclude the 35-year-old Serb from the tournaments at Indian Wells and Miami Open in March.
Dubbed the "Sunshine Double", they are part of the Masters 1000 series and considered to be among the most esteemed events on the ATP circuit after the four Grand Slam competitions in Melbourne, Paris, London and New York.
Djokovic has spoken candidly about the reasons why he has not been vaccinated against the coronavirus. His stance led him to missing the events last year.
It also prevented his participation at the 2022 US Open in New York. However, he was able to play at the French Open in Paris and Wimbledon.
The Serb is in Australia continuing his preparations for his tilt at a record-extending 10th Australian Open.
In 2022, he was deported from the country for falling foul of Australian anti-coronavirus laws.
Those regulations have since been relaxed and foreigners no longer need to show they have been vaccinated against the disease to enter the country.