The line said that following the US Centers for Disease Control’s decision to extend its no-sail order until 31 October, it now deemed November operations "unfeasible".

After the new order was issued, Carnival initially cancelled all cruise operations but those due to depart Port Miami and Port Canaveral.

It has also cancelled five cruises scheduled to operate from Sydney, departing variously from 16 January 2021 to 8 February 2021.

Carnival said it would continue to work on protocols and procedures to mitigate Covid risk and allow it to resume cruise operations safely.

This will start in a gradual, phased manner, with Port Miami and Port Canaveral serving as the first two homeports for new embarkations.

"Cruises currently scheduled for December from those two homeports remain in place for the time being while Carnival evaluates options," said the line in a statement.

"However, guests booked on cruises in December out of Miami and Port Canaveral still have the ability to voluntarily cancel their reservation and receive the same offer that all other impacted guests are receiving, which includes a combination future cruise credit and onboard credit, or a full refund."