P&O Cruises has cancelled trips until November.
The tour operator has also axed two cruises with longer itineraries that were due to begin in January 2021.
The firm had previously cancelled sailings until October 15.
The UK's largest cruise line said this was due to the Foreign and Commonwealth Office advising people to avoid cruises.
As a result, P&O Cruises has extended the suspension of sailings until at least November 12.
P&O Cruises president, Paul Ludlow, said: "It is clear that whilst the guidance is in place it is not advisable for us to resume operations.
"As well as cancelling all cruises up until November 12 we will, sadly, also be cancelling Aurora’s Caribbean and South America Adventure and Arcadia’s World Cruise.
"Given long-term planning, combined with the complexity and length of these long-haul itineraries and evolving border restrictions, we need to ensure that we adhere to the guidance as it stands.
"I know that these January cruises, in particular, are holidays of a lifetime and we are so sorry for the disappointment that these cancellations will cause."
