Novak Djokovic has tested positive for the coronavirus after taking part in a tennis exhibition series he organized in Serbia and Croatia.

The top-ranked Serb is the fourth player to test positive for the virus after first playing in Belgrade and then again last weekend in Zadar, Croatia.

His wife also tested positive.

"The moment we arrived in Belgrade we went to be tested. My result is positive, just as Jelena's, while the results of our children are negative," Djokovic said in a statement. "Everything we did in the past month, we did with a pure heart and sincere intentions. Our tournament meant to unite and share a message of solidarity and compassion throughout the region."

Djokovic has been criticized for organizing the tournament and bringing in players from other countries amid the coronavirus pandemic. There were no social distancing measures observed at the matches in either country.

Viktor Troicki, Grigor Dimitrov and Borna Coric also all tested positive.

"We organized the tournament at the moment when the virus has weakened, believing that the conditions for hosting the Tour had been met," Djokovic said in the statement. "Unfortunately, this virus is still present, and it is a new reality that we are still learning to cope and live with. I am hoping things will ease with time so we can all resume lives the way they were.

"I am extremely sorry for each individual case of infection. I hope that it will not complicate anyone's health situation and that everyone will be fine. I will remain in self-isolation for the next 14 days, and repeat the test in five days."

Djokovic has said that he wasn't sure if he would receive a vaccine if it becomes available even if it was mandatory to travel on the tour.

Information from The Associated Press was used in this report.