World No. 1 Ashleigh Barty, from Australia, previously said that she won't travel to the United States in the current conditions, and similar reservations—though no confirmation—has been expressed by the tour's No. 2, Simona Halep.
Both Svitolina, a semifinalist at last year's US Open, and Bertens, who has never surpassed the third round at Flushing Meadows, would have had opportunities to win their first Grand Slam titles in a depleted field.
"Considering all the aspects, I have decided not to play the US Open 2020," Svitolina shared on Twitter. "I want to thank the USTA, organizers and the WTA for giving the players a chance to play and the fans a chance to watch this great event.
"I understand and respect all the efforts they are putting to make it happen in a safe environment, but I still don't feel comfortable to travel to the US without putting my team and myself at high risk."
On Instagram, Bertens expressed the same concerns as Svitolina, and also spoke to the mandated 14-day quarantine that players could be forced to do upon return to Europe.
"After long consideration I have decided not to go to the states for Cincinnati and the Us open," wrote Bertens. "The situation around COVID-19 is still that worrying and the health of everyone and the control over this virus is priority.
"Our prime minister indicated yesterday that we should be quarantined for 14 days after coming back from the states. Off course we respect this as a team and this would disturb our preparation for my beloved clay court tournaments in Rome and Paris. I hope the situation will soon take a positive turn and wish everyone good health."
We will continue to update this developing story.