The 2021 Para-cycling Track World Championships will no longer take place in Rio de Janeiro, Brazil because of the Covid-19 pandemic.
The event was due to begin on 25 March but organisers are now looking for a new host nation.
The sport's governing body, the Union Cycliste Internationale (UCI), says the cancellation follows "restrictions by the authorities".
"We are currently looking for a solution," said the UCI.
"The UCI shares the disappointment of the para-cycling community and thanks the organisers of the event for their cooperation in these difficult circumstances."