Nick Kyrgios slammed the ATP as "selfish" Thursday for pressing ahead with plans for the US Open despite the country dealing with a coronavirus pandemic and widespread anti-racism protests.

The temperamental Australian suggested it was too early for the Flushing Meadow Grand Slam, joining other players in expressing reservations, including world number one Novak Djokovic.

"The ATP is trying to make the US Open go ahead. Selfish with everything going on at the moment," Kyrgios, ranked just 40 but a showman who is popular with fans, said on Twitter. 

"Obviously Covid, but also with the riots. Together we need to overcome these challenges before tennis returns in my opinion."

The tennis season has been on hold since mid-March because of the pandemic, with the French Open postponed and Wimbledon cancelled. 

The US Open is still scheduled to go ahead, with the main draw starting on August 31 despite New York being the epicentre of the outbreak in the US.

Authorities and organisers have drawn up a list of hygiene rules, including a 14-day quarantine period for players arriving in the United States while restricting their entourage to one person.

Djokovic suggested on Wednesday that he may skip the North America swing and restart his season on clay in Europe in early September, complaining about the "very severe" measures being put in place at the US Open.

"Most of the players I've talked to so far have a rather negative view of the possibility of going," said the Serb.

World number two and reigning US Open champion Rafael Nadal has expressed similar reservations, while top-ranked woman Ashleigh Barty has also voiced caution about resuming tennis too soon.