Strade Bianche has been cancelled.
Uncertainty over the fate of the 2020 edition was rife due to the spread of coronavirus in Italy, as a number of teams had already pulled out of the race.
The organiser of Strade Bianche, RCS Sport, informed teams that the race will not be held on Saturday (March 7) and then released a public statement.
No announcement has been made about Tirreno-Adriatico or the first Monument of the year, Milan-San Remo.
The statement from the organiser said: "RCS Sport has agreed with the appropriate authorities to cancel the two cycling races scheduled for Saturday: Strade Bianche and Strade Bianche Women Elite.
"RCS Sport will request the UCI, via the Italian Cycling Federation, to allocate a new date on the international cycling calendar for Strade Bianche and Strade Bianche Women Elite."
The organiser met with the Mayor of Siena on Thursday morning (March 5) and confirmed it would not be able to meet the restrictions set out by the Italian government for holding a sporting event during the outbreak.
Ag2r announced they would be pulling out of Tirreno and San Remo scheduled for this month to protect the health of their riders.
Team manager Vincent Lavenu said: "I cannot risk the health and integrity of our staff when the health situation is so unstable in Italy, and many legitimate questions have been raised within the team.
"Sporting interests should not overshadow prudence and wisdom when it comes to public health. We are very sorry for the organisers of these legendary races and we have informed them this morning of our decision."
The chances of the Italian spring races being held fell dramatically when the Italian government banned all public sporting events on Wednesday evening (March 4), as a measure to slow the spread of the Covid-19 virus.
Six Nations rugby matches are due to be held behind closed doors while Serie A football matches in Italy have been postponed, but it was unclear what the decision meant for a bike race held on public roads.
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A number of top-tier teams had already announced they would not be racing in Italy in the coming weeks because of concern for the health of their riders and due to the risk of spreading the virus further.
Women's UCI team Parkhotel Valkenburg were the first to announce they would not race in Siena or the Trofeo Alfredo Binda, with Jumbo-Visma, Team Ineos, and Astana also withdrawing from races.
