He said he will self-isolate for the next 14 days.

Tennis champion Novak Djokovic said Tuesday he has tested positive for COVID-19.

His wife also tested positive but their children are negative, he said.

Three tennis players competing at a tournament Djokovic organized in Croatia and Serbia have tested positive. All matches have been canceled.

Djokovic, who ranks No. 1 in the sport, defended his tournament, saying it was “meant to unite and share a message of solidarity and compassion throughout the region.”

“The Tour has been designed to help both established and up and coming tennis players from South-Eastern Europe to gain access to some competitive tennis while the various tours are on hold due to the COVID-19 situation,” Djokovic said in a statement. “It was all born with a philanthropic idea, to direct all raised funds towards people in need and it warmed my heart to see how everybody strongly responded to this.”

“We organized the tournament at the moment when the virus has weakened, believing that the conditions for hosting the Tour had been met,” he said. “Unfortunately, this virus is still present, and it is a new reality that we are still learning to cope and live with.”

Djokovic said he will self-isolate for the next 14 days and retake a coronavirus test in five days.

ABC News’ Dimitrije Stejic contributed to this report.