Organisers of Sydney's Royal Easter Show say it has been cancelled due to the coronavirus pandemic — the first time in almost a century the show has been abandoned due to public health concerns.

It comes after the Prime Minister Scott Morrison announced the cancellation of non-essential mass gatherings of more than 500 people from Monday.

Royal Agricultural Society (RAS) president Robert Ryan said it was very disappointing to have to cancel.

"This is the first time the Sydney Royal Easter Show has been cancelled because of a public health emergency since the Spanish flu pandemic in 1919," he said.

The show was due to begin on April 3 and more than 800,000 people were expected to attend the 12-day event.

RAS chief executive Brock Gilmour said the show generated more than $250 million in economic activity each year and cancelling it would cost the RAS "tens of millions of dollars".

He said the RAS was in the process of dealing with issues such as refunding tickets and competition fees and unwinding contracts with hundreds of suppliers, which was expected to take weeks.

"The RAS, we survived the 1919 Spanish flu pandemic, we survived the Great Depression, we survived WWII and we will survive coronavirus — and the show will be as big bold and exciting as ever in 2021."

In a statement on its website, the RAS said the decision was made "for the safety and wellbeing of our patrons and visitors".

Minister for Agriculture Adam Marshall said he was "absolutely devastated" by the cancellation but understood it was important to protect public health.

"It's truly heartbreaking for everyone involved and another bitter blow on top of a rough 12 months of drought and bushfires," he said.

"The show is a rare opportunity for farmers to come together, celebrate all that is great about agriculture and share what they do with the city."

Australia's chief medical officer Brendan Murphy told leaders at a COAG meeting on Friday that mass gatherings of more than 500 people should be cancelled.

Mr Morrison said the cancellation would not be extended to schools, universities, public transport or airports.

"It is precautionary. It is getting ahead of this to ensure that we can minimise the impact on your health and [so] we can ensure with confidence the ability for people to be accessing the health services that they and their families will need," Mr Morrison said.

A number of events have already been cancelled, including the Melbourne Grand Prix, Dark Mofo in Hobart and the NSW Blue Mountains Music Festival.

NSW today reported its biggest daily jump in coronavirus cases, bringing the total number of confirmed cases in the state to 92.

Fourteen new cases were diagnosed, including at least seven people who have recently returned from international travel.

An aged-care worker, who has been in contact with other confirmed cases, was also infected.

Authorities say one passenger travelled on Emirates flights on Sunday, March 8 and they are looking to contact passengers seated nearby.