Novak Djokovic will miss the US Open, which begins on Monday in New York, due to vaccination restrictions.

Djokovic, who has refused to be vaccinated against COVID-19, making him unable to travel to the United States, took to Twitter on Thursday to announce the news.

“Sadly, I will not be able to travel to NY this time for US Open,” he wrote. “Good luck to my fellow players! I’ll keep in good shape and positive spirit and wait for an opportunity to compete again. See you soon tennis world!”

Back in January, Djokovic was granted a vaccine exemption to enter Australia and play in the Australian Open after recovering from COVID-19. He subsequently missed the tournament, after judges upheld a decision by the immigration minister to revoke the Serbian tennis star’s visa.

The news arrives with Djokovic looking to tie Rafael Nadal’s 22 grand slam wins for the most major titles in men’s tennis history. After securing his 21st grand slam win in July at Wimbledon, Djokovic maintained that he will not get vaccinated. 

“I’m not vaccinated and I’m not planning to get vaccinated so the only good news I can have is them removing the mandated green vaccine card or whatever you call it to enter United States or exemption,” Djokovic said at the time. 

The US Open begins next week at Flushing Meadows-Corona Park in Queens, New York.