The Ryder Cup has been suspended for a year.
Padraig Harrington was due to captain Europe in their defence of the trophy against the US at Whistling Straits in September.
The postponement follows advice from medical experts and the public authorities in Wisconsin.
The competition will be held instead from 21-26 September 2021.
It also means that Adare Manor's hosting of the Ryder Cup is pushed back a year to 2027.
"Rescheduling the Ryder Cup was never going to be an easy decision given the many factors to take into consideration," Harrington said.
"But I believe it is the right assessment given the unprecedented circumstances we are facing at this time.
“When you think of the Ryder Cup you think of the distinctive atmosphere generated by the spectators, such as around the first tee at Le Golf National two years ago. If that cannot be responsibly recreated at Whistling Straits in September, then it is correct that we all wait until it can be.
"I know, right now, that September 2021 feels like a long time away. But it will come around quickly and I guarantee that the European players and I will be ready when it does."
Other options were explored according to Europe's Ryder Cup director, Guy Kinnings, "We considered all options including playing with a limited attendance but all our stakeholders agreed this would dilute the magic of this great occasion."
The Ryder Cup's suspension has had a knock-on effect on the President's Cup.
Originally slated for September 30-October 3, 2021, at Quail Hollow Club in Charlotte, North Carolina, it will now be played September 19-25, 2022.
"Unlike other major sporting events that are played in existing stadiums, we had to make a decision now about building facilities to host the 2020 Ryder Cup at Whistling Straits,” said PGA of America CEO Seth Waugh.
"It became clear that as of today, our medical experts and the public authorities in Wisconsin could not give us certainty that conducting an event responsibly with thousands of spectators in September would be possible.
"Given that uncertainty, we knew rescheduling was the right call. We are grateful to PGA TOUR Commissioner Jay Monahan and our partners at the TOUR for their flexibility and generosity in the complex task of shifting the global golf calendar."